242 99PRrMKI3 I MN

COUNCiL OFRESEARCH IN

WATER RESOURCES

Proceedings

NationalWorkshoponQuality of Drinking WaterMarch 07, 1998Islamabad,Pakistan

CompiledbyDr BashirA. ChandioDr MuhammadAbdullah

Jointly OrganizedbyPAKISTAN COUNCIL OFRESEARCh INWATERRESOURCESANDCHEMICAL SOCIETYOF PAKISTAN

Proceedings

of the

National Workshop onQuality of Drinking Water

March 07, 1998Islamabad, Pakistan

Compiledby

Dr. BashirA. Chandio

Dr. MuhammadAbdullah

PakistanCouncilof ResearchinWater Resources(PCRWR) Islamabad

LIBRARY lAGP0 Box 93190, 2509 AD THE HAGUE

TQI. +31 703068980Frnc. +31 70 35 89964

BARCODE: J~jj~çyLO:

1999

© PCRWRILDIC 19993 Street17, F-612, IslarnabadPakistan

ISBN 969-8469-O1-X

PREFACE

Water is the fountain of life andis indispensiblefor its continuity Though it is earth’s

one of the most abundantsubstancesbut is rarely found in its pure form becausebeing a

universalsolvent it is either a vehicleor storageof variouspollutants The consequentscarcity

of potable water has Lceated the real problems of human health and environmental

sustainability Keepingin view the paramountimportanceof drinking water, the PCRWRand

CSPhave put their modestefforts to orgamzea one day “National Workshop on Quality of

Drinking Water” The papersand subsequentdiscussionshavecovereda wide spectrumof

drinking s~dterquality

I feel immensepleasureto acknowledgethe efforts of organizersto conduct this

workshopvery effectively. I am cognizantthat all dimensionsof the drmking water quality

are not comprehensivelydiscussedin this workshop,however,it givesme greatersatisfaction

to see that workshopproceedingsare properly documentedand published.I would put my

efforts to bring theserecommendationto tne notice of plannersand decisionmaker so that

futureplanningcarriessomeflavor of this workshoprecommendations

Dr. BasbirA. ChandioChairman

PakistanCouncilof Researchin WaterResources(PCRWR)

(i)

TABLE OF CONTENTS

PREFACE

INAUGURAL SESSION

Workshop Brief Dr Din Mohammad,Secretaiy,WorkshopOrganizingCommittee 3

WelcomeAddress U Gen.(retd) JavedAshrafQazi, 5

Secretary,Ministry ofScience& Technology

Role of Industry in Safe Drinking Water Mr Khaiii-ur-Rehman,GeneralManager 6HimalayaMountain ValleyWater (Pvt ) LimitedIslamabad

Key NoteAddress Dr. Ba.shirAhmedChandio, Chairman,PCRWR 7

Inaugural Address SyedaAbidaHussain,FederalMinisterfor Science& Technology 9

Vote of Thanks Prof. RoshanAhmad, Chairperson, WorkshopOrganizingCommittee 11

TECHNICAL PAPERS

Drinking WaterQuality andStandardizationin Pakistan 14Dr. BashirA. Chandio,Dr. M. Abdullah and M. A. Tahir

EnvironmentalPollution and Carcmogenesis 19Dr. S.Riaz-ud-Din

WaterBorneDiseases 22Dr. KhurshidAhmed& Dr. Arhar SaeedDii

DrinlungWaterQuality GuidelinesValues ChemicalandPhysicalAspects 25S. Shujah& M Jaffar

MembranesandotherProcessesto Improve the Quality of DrrnkmgWater 29MuhammadAshrafChaudhry

SeparationandSpeciationof Organo-PhosphorusPesticidesBasedon 33HydrolysisUsingReversePhaseHPLCJasminShah,M.RasulJanandKahkeshanSaeed

Drinking WaterQuality Momtormg in the RuralAreasof Rawalpindi 35M AslamTahir, Dr. BashirA Chandzo,Dr M Abdullah& AbidRashid

SyntheticInorgamcIon Exchangers:Efficient Scavengersfor 40Toxic Pollutantsm WaterSyedMoosaHasany

WaterChemistry,Quality Control by ElectrochemicalMethods 43RiazAhmed

Nitrate Pollution in Drinking Waterand its Measurement 47MuhammadMans/ia Chaudhry,Tariq M Naeemand Asmatullah

Analysis of PotableWater in DeraGhaziKhan 50RizwanHussainandAbdulMateen

ABSTRACTSOF SELECTED PAPERS

CleanandSafe Drinkmg Waterfor All 54MuhammadAkramChughtai

Quality Control of Drmking Water 54Mian Muhamnw.dAslamParametersof WaterQuality 54Dr lqbai H. Qureshi

RECOMI~VEENIIATIONS 56

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INAUGURAL SESSION

Workshop BriefDr.Din Mohammad, Secretary, Workshop Organizing Committee

WelcomeAddressLt.Gen.(retd) Javed AshrafSecretary, Ministry of Science& Technology

Roleof Industryin SafeDrinking WaterMr. Khalil-ur-Rehman,GeneralManagerHimalaya Mountain Valley Water (Pvt.) Limited, Islamabad

Key Note AddressDr. BashirAhmedChandioChairman,PakistanCouncil of Researchin WaterResources

Inaugural AddressSyedAbida HussainFederalMinister for Science& Technology

Vote of ThanksProf. RoshanAhmadChairperson, Workshop Organizing Committee

WORKSHOP BRIEF

Dr. Din Mohanunad,Secretary,WorkshopOrganizmgCommittee

SyedaAbida Hussain, FederalMinister for Science& TechnologyLt Gen (retd)JavedAshraf Qazi, Secretary, Ministry of Science& TechnologyDr. BashirAhmedChandio,Chairman,PakistanCouncil of Researchin WaterresourcesProfessorRoshanAhmed,Chairperson,WorkshopOrganizingCommitteeMr Khalil-ur-Rehman,GeneralManager,HimalayaMountainValley Water(Pvt) LimitedMembersof the OrganizingCommitteeDistinguishedGuests, Ladies and Gentlemen’

Assaiam-o-Alaikum’

It gives me a greatpleasureto well comeyou allto this occasionandpresentmy brief reporton thisworkshop

In January / February 1994 we experiencedspreadof Hepatitis epidemic in parts of Islamabadwhich was later tracedto be linked to the use ofcontaminatedwater. Thismay havehappenedduetoa statistically possible human error or improperplanning and management of the water supplysystemof the area Theremay havebeenmany suchincidents frequently occurring un-noticed in ourbelovedcountryelsewhere

In line with the recent trends locally bottledmineral water supplies are now available in themarketbeing respectableand clean industry andnodearthof the raw material Yet onemay haveheardsomeone’s whisperexpressinghis displeasureoverthe quality suspectingthat some one might havebottledit from a sourcewithout proper treatment Ithas also cometo our notice that a few foreign basedagencies have expressedtheir disbelief on thequality of the locally manufacturedbottledwater

Under such situation, keeping in view the factthat our belovedland had been bestowedupon byThe Almighty Allah the best quality waterresourcesin the world, the scientific communityrepresentedby the CSPand PCRWR feeling it to betheir National duty, joined hands to hold thisworkshop to achievethe following objectives

To createawarenessamongstthe massesfor aqualitywater as a commonresponsibility

To bring the scientific community, govtagencies,organization such as the CDA and themanufacturing industry on a common plateformconsidering it a National requirementto improveuponthe quality of drinking water

To create further interaction between theworking scientists, theoretically strong scientistswith academicand researchresponsibilitiesand theindustry for collaborativeR&D required to achievethe cherishedgoal

To label the available facilities which could beemployedI approachedto get quality analysis

To create scientific activities in collaborationwith NGO’s such as the chemicalsociety,PCRWR,EPA, universities and the industry for regularintercomparisoncampaignsfor analysisof drinkingwater samples Such activity would lead tocertificationof laboratoriesfor qualityanalysis.

Apart from the inaugural and the concludingsessionsthe whole activity has been divided intothree sessions technical session-I, commercialsession and technical session-Il In the techmcalsession-I four invited lectures based on differentaspectsby experiencedandknowledgeablescientistsand professionals such as Dr. I. H Qureshi,Scientist Emeritus PINSTECH, Dr. S RiazuddinProfessor and Director, Centre of Excellence inMolecular Biology, Punjab University Lahore,Dr Khurshid Ahmed,KRL Hospital, IslamabadandDr M Jaffar, Quaid-i-AzamUniversity, Islamabadwill be presented This will be followed bycommercialsessionwheremostof the invitedpapersbelong to the industrial sector This has been doneso intentionally in order to record meaningfulparticipationof the industrialsectorin suchnationaland scientific activity and I am pleasedto informyou that we have received enthusiastic responsefrQm the industrial sectorso much so that we faceddifficulty in arranging the allotted time to thespeakers Keeping in view the importance of theoccasion we have accommodated everybodyHowever the time allotted has been decreasedtoonly ten minutesto eachand I would requestto allspeakers to strictly follow the timing and givemaximum meaningful intormation to the audienceIn third sessionwe haveincluded two invited papersand the rests are scientific papers which thescientistsand engineerswould like to presentandare basically concerned with the processor theanalytical techniquesrequired for quality analysis inone way or the other This will be followed by theconcluding session which would include a brief

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report on the workshop proceedings,recommendationsfor the future and concludingaddress by the Chairman concluding sessionDr. A Q. Ansari Chairman PCSIR LaboratoriesIslamabad

This occasionis bemgsponsoredby three typesof sponsors:

(a) Bottled mineral water manufacturers and I wouldlike to mention their namesas under:

(1) M/s Himalaya Mountain Valley (Pvt.).Limited,

(2) M/s Natura, Natural Mineral water,Islamabad;

(3) M/s Sparklette Continental Corporation,Limited, Islamabad,and

(4) MIs Northern Bottles (Nt.) Limited,Islamabad.

(b) Manufacturefsof the filtered systemsand here Iwould like to mentionthe following names

(1) M/s ServiceIndustries,Lahore;

(2) MIs Arco Intemational,Rawalpindi,and

(3) M/s So-Safe Water Purification Product,Islamabad

(c) Suppliers of Scientific Equipment and alliedproductsrequiredfor quality analystsof water. Iwould like to mention the namesas:

(1) M/s Faiz Enterprises,Islamabad;

(2) M/s We Brothers Scientific Works,Islamabad,and

(3) M/s H A Shah & Sons Islamabad.

We have been rather conservative in choosingthe sponsors becauseof the reason that we onlywanted competent companies to be associated withus at this first instance. I thank all for theircooperationandhopethat this will be for our mutualbenefitsand servicein the National interest.

Thankyou all

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WELCOME ADDRESSLt. Gen.(retd) Javed Ashraf Qazi

Secretary, Ministry of Science and Technology

Syeda Abida Hussam, Federal Minister for Science and TechnologyDr Bashir Ahmed Chandio, Chairman, PakistanCouncil of Research in Water ResourcesProf. Roshan Ahmad, Chairperson, Workshop Orgarnzmg CommitteeMr Khalil-ur-Rehman of Water IndustryDistinguished Delegates, Ladies and Gentlemen!

Assalam-o-Alazkum!

It is indeed a pleasurefor me to make thiswelcome address I am happy to see that ourscientific organizationshavebecomeactive and arenow interacting with industrialists as well as withothermembersof scientific communities This typeof interaction, mter-discussion and barter ofscientific and technological knowledgeamong theresearchers, scientists, suppliers and consumersshouldresult m developmentandprosperityfor ourcountry. Undoubtedly, water is the most essentialconstituentof life. A personcan live without foodfor sometime but not withoutwater Life would beadversely affected if there were too little or toomuch water and would be miserablewith pollutedwater.

The concept of pure water is a pre-historicnecessitywhenmethodsof water purification wereprescribed There are a number of verses in theHoly Quranand sayingsof our Holy Prophet(Peacebe Upon Him) about importanceof cleanwater andits requirement for drinking, washing and bodycleaning before prayers The flowing water withoutbad odour andchanged colour used to be declared asclean However, new venues of impurities andpollution have now emerged which are to beresolved through scientific innovations. Thesecontaminationsandpollution are the after-mathsofmodern civilization, unchecked industrial growthand callous disregard for our environment madeworse by rapid populationgrowth. People living indeserts, villages, towns and big cities take thequality of drinking water at different standardsSomemay considerpoor quality water fit for usebecauseof its acceptableappearance,tasteandodor,but it may not be true when analyzed on WHOstandards.In contrastto that someonemay consideronly the deionizedwater fit for their health.Thus it

is essentialto educatethe society about the actualrequirementof the qualityof drinking waterand thisis themain themeof this workshop.

The first step toward the establishment ofstandardsto ensurethe safetyof water suppliesis to

agree upon some criteria for safety. It is well knownthat the water supplies of many of our large citiesand towns are poor which is established by the factthat the large cities have, in recent years, sufferedmaximum incidence of waterborne infections anddiseasesWaterhas beenidentified as main diseasesvector for dangerousdiseaseslike Hepatitis. Therisks of infections and diseasesthrough drinkingwater are much higher ut developing countriesbecauselackof quality control measuresandqualitystandards.

It is hoped that the latest developmentson thissubject will be presentedand discussed in this~‘orkshop.A deeperunderstandingof the drinkingwater quality under present circumstancesshouldresultin evolving a suitablestrategyfor future waterdevelopmentand managementprogrammes Youhave a limited time of five hoursafter the inauguralsession,nevertheless,I would like to suggestthatthe workshopshouldfocus on someof thekey issuesin its recommendationswhich may include thedevelopment of the water resources and itsenvironmental protection, water scarcity and itsimpact on rapidly expandingurban populations; thedevastating effects of water-borne diseases onhuman health, the involvement of people inmanagmgtheir own water systemsandresearchonnew frontiers of water developmentandmarketing.In this regard the adverseimpacts of sub-standardwater on mfantsand femalepopulationshouldnotbeforgotten

Madam Minister, Distinguished guests andparticipants, m the end I welcome you to thisWorkshopand I am grateful to you that you havespared your valuable time to be with us today. I amspecially grateful to the managersof water industryfor co-sponsormg this Workshop. Your presence atthis forum indicates your interest and your viewsexpressed candidly will lead to improvements in thisvital sector.

Thankyou.

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ROLE OF INDUSTRY IN SAFE DRINKING WATERMr. Khalil-Ur-Rehman, General Manager

HimalayaMountainValley Water (Pvt.) Limited, Islamabad

MohtermaSyedaAbida Hussain,FederalMinister, Ministry of Science& TechnologyLt Gen (retd) JavedAshraf Qazi, Secretary,Ministry of Science& TechnologyDr Bashir Ahmed Chandio,Chairman,PakistanCouncil of Researchin WaterResourcesProfessorRoshanAhmad, Vice President,The ChemicalSociety of PakistanDistinguishedGuests,Ladies andGentlemen’

Assalam-o-Alaikum!

I feel greatlyelatedto welcomeyou on behalfofwater industry of Pakistanto this well organizedworkshop on quality of drinking water Oneof thebasicrequirementsfor the developmentof science&technologyis a mutual communicationbetweenthetechnicalpersonnel’s.Sucha dialoguebreacha newideasand upto datescientific knowledgeamongsttheprofessionals Similar exchangeat national levelbrings for an opportunity not only for a thoughtprovoking reviewof the national technicalproblemsbut also ways of solving them through latestdeyelopmentsabroad

Ladies and gentlemen I am really grateful toPCRWRandCSPwho haveworked hardto providea common platform to the scientists, industrialistsand the consumerof the drinking water We candiscussthe problemsfacedin bringing the quality ofdrinking water, gain knowledgeand help eachotherto meet this national problem I am sure scientistswill be dealingwith the water samplingtechniques,procedure, water quality testing for aesthetic,physical,chemical and micro- biological parametersalongwith the water quality standard and alegislation We the people from industry will bediscussing our products, the source of water,method employed for its purification, plantprocessing anduse of different typesof filters Thedelegates from M/s Ava, M/s Nautra and M/sSparkletts are here who are in the water field Ihope we will be benefiting from them As far asHimaliya Mountain Valley Water Pvt Limited isconcernedweare servingfor the last threeyears

I would like to give a brief introductionof ourcompany The plant is situated in Abbottabadandour source of water is Himalaya Mountain ValleySpringWater which is further processed,filled andmarketed We have state of the art machinery

imported from America and Italy which includesbottling plant from M/s Uniloy of America capableof making 2800 PETbottles per hour. Two waterpurifying capsulesand multi mediafilters from M/sAqua of San Jose,California, which are filled withimproted silica sand,Charcoaland gravel, then wehaveprocessingplant from Italy consistingof rinser,filler, capperand labeler with a capacity of filling4500 bottlesper hour Our filled bottle is touchedbya human hand only when it comes out of thelabeling machineand remainsuntouchedby humanhandthroughoutthe filling process.

For disinfection of water we have imported anozonegeneratoralso from Americawhich~ozonizesthe water during the filling processfor disinfection.We haveengagedprofessionalchemistswho remainbusyin our well equippedlab. To keepstrict checkon the quality of water and under no circumstancescompromiseon quality We sendour water samplesfor periodical analysis to Fresenius institute andAlteapothekeof Germanyandin Pakistanto PCSIR,Shifa International, CMH, Agha Khan UniversityHospital and QualitestLaboratoryKarachi.

As far as our distribution is concernedwe haveacomplete network of distributors all over Pakistanwho are responsiblefor distribution of our product.While our institutionalsales are looked afterby ourcompanyitself throughour two offices in IslamabadandKarachi

Ladies and gentlemen, I hope the scientificexchangeduring this oneday workshopon quality ofdrinking waterwill resultin achievingour objectivesof coordinatedefforts for this National issue. I wishall the best.Thankingyou very much

KhudaHafiz, PakistanPaindabad’

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KEY NOTE ADDRESSDr Bashir Ahmed Chandio

Chairman,PakistanCouncil of Research in Water Resources, Islamabad

Syeda Abida Hussain, Federal Minister for Science & TechnologyLt. General (retd) JavedAshrafQazi, Secretary,Ministry of Science& TechnologyProf RoshanAlimad, ChairpersonWorkshopOrgarnzmgCommitteeMr Khalil-ur-Rehman,of WaterIndustryDistinguishedDelegates,Guests,Ladiesand Gentlemen’

Assalam-o-Alaikumt

It is indeed an honour for me to present mysemi-technical paper before the distinguishedaudience I feel pleasureto say that the PakistanCouncil of Researchin WaterResources(PCRWR)and Chemical Society of Pakistan (CSP) arepioneers in organizing National Workshop onQuality of Drinking Water in Pakistan Previously,the Scientists, Engineers, Industrialists andProfessionalsdealing this subject were encircledwith their researchand developmentactivities inisolations In order to break this isolation andbashfulness, CSP and the PCRWR have joinedhands and have provided a common platform forpersonnelsandfirms to exhibit as well as introducetheir latest technologies and recent researchfindings

Thewater we usefor domesticpurposesis beingpolluted from different sources.The one that isbeing conveyed through pipe lines is pollutedbecauseof defective joints and damagedconduits,and the one routed through open system iscontaminated by chemicals of municipal andindustnalwastes,andpesticidesand insecticidesofagricultural fields. Due to these and many othercontaminations, the drinking water is becomingunsafe to consume The polluted water has turnedup as one of the leading health challengesin theworld todaybecauseit is creating diseases,creatingphysical and mental disorders,causingcancer andmany othersattacking intestine, stomach,liver andkidneys

According to recentWHO estimates27% of theworld population lives without a clean and safesupply of water. The caseof Pakistanmay evenbeput at low ebbof sanitationand safe water supplystandards,though in population it is the 9th mostpopulouscountry in the world In Karachiandothermajor cities, more than 80% of the populationhasno accessto clean potablewater. Only in Karachi60% of all hospital admissionsare due to water-bornediseasesIt hasbeenestimatedthat some57%of the total deaths in Pakistanare causeddue to useof contammatedwater while figureshavegone upto60 percentfor children It hasbeenestimatedthat inthis country some 10,000personsdie every yeardueto kidney-related diseasescaused by drinking ofdirty water Infant morbidity is so serious that more

than 100 infants die every day because of pollutedwater

Unfortunately both the public as well as privatesectorsare polluting water bodies at one or anotherpretext or disguise If 90% of the industrialestablishmentsdoesnot havewater treatmentplantsand are disposingtheir effluentdirectly or indirectlyinto the rivers and lakes, the caseof public sectorlike WAPDA also cannotbe quoted as satisfactoryMost of the SCARPs are discharging theircontaminatedfield drainageeffluent into fresh waterbodies, sothat not only the salinity and pollution ofthe Indus river water rises but also it becomesmoreandmore toxic as it travels southward

In order to make the systemself sustained,thewater managers have to levy water chargesaccording to volume consumed. However,willingness to pay for improvements in drinkingwater quality only increaseswith increasein incomeand level of education Thuspublic understandingofwater quality is must. It is believed that sourceprotectionremains the most reliable and low-costmethodcurrently available to protect drinking waterquality Many decision makersconsiderthat insteadof spendinghuge resourcesto control water bornediseases,one should focus on preventionmethodsandthat with the useof cleanand purewater, countrycanprevent water-borne diseases to a greater extentthough debateis open about fixmg the standardsforboth microbiological and chemical parameters.Asthe demandfor clean drinking water has increased,the industrial communitieshavealso diverting theirresourceson marketingof drinkingwater.

The Governmentof Pakistanis very much aliveto shortage of safe drinking water. It has setfourteen national conservation strategies andpriorities under the development programme of2010 namely.

• protectmg water bodies and sustainingfisheries,

• increasingirrigation efficiency,• protectingwatersheds,• conservationof croplands,• supportingforestry andplantation,• restoringrangelandsand improving livestock;• conservingbiodiversity;• increasingenergyefficiency;

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• developing renewable resources,• preventing andcombating pollution;• managing urbanwastes;• supporting institutions for common resources,• integrating population and environment

programmes; and• preserving the cultural heritage.The mother nature has ensured unpolluted supply

of water through hydrologic cycle but man madeinterventions, human greed and unscientificmanagement have tended to pollute this supply lineFor example, disposal of untreated industrial andmunicipal wastes is introducing dangerously highlevels of toxic pollutants into our rivers, reservoirs,lakes In Kasur 109 tanneries are poisoning thegroundwater. In Lahore, more than 10 milliongallons comprisedof raw sewage,industrialwastesand the run-off from chemicals, fertilizer andpesticideunits aredumpedinto the Ravi River everyhour. The 94% untreated water in Karachi isdischargedinto the Lyari and Malir rivers whichcauses deoxidation, kills the aquatic life andgeneratesunpleasantodours.

A study conducted by the Health ServicesDepartmentof the KMC shows that out of 372samplesof drinking water 340 were found unfit forhuman consumption as E-coli bacteria weredetected This findmg indicates that sewage waterwas being mixed with the drinking water supplysystem Reports prepared by organizationsotherthan the KMC havealso indicated the presenceofpathogensand turbidity in Karachi’sdrinking water.The situation of twin cities of Islamabad andRawalpindi is also not too different becauseabout40% populationis usingpoor quality drinkingwaterAs a result of this uncontrolled and unmonitoreddisposal of wastes, into water bodies, the principalsourcesof drinking water are progressivelygettingpolluted.

Groundwateris a main sourceof drinking watersupply all over the world The fresh water aquifersare being treatedas good sourcesof quality waterThey are prone to salt water intrusion and upconingbut were always takenunaccessibleto chemicalandpathogeniccontaminationsthat caseno more existsThe analysis of groundwaterfrom wells, tubewellsand hand pumps shows that it is invariably pollutedand is unfit for human consumption In developedcountries, groundwater managementis thought bythe usergroups to be better than its treatment,andlocal and state level involvement is favouredoverfederalintervention.

All my this discussionis as a matter of factaimed at knelling bells of danger that our waterresourcesare being pollutedat suchan alarmingratethat we are left with little time to waste Thecontaminationof our water sourcesand resourcesfrom nuclear and other lethal wastes is yet to bedetermined. It is thereforevery important that thewater quality all over Pakistanis monitored by anumbrellafederalorganizationsregularly. I can quote

the exampleof Malaysia where the need for thedevelopment of a national program for surveillanceof drinking water quality was identified in 1983becauseit was presumed that the quality of rawwater sources would deteriorate further withincreasing urbanization and development. Hence thenational drinking water quality surveillanceprogramme was launched to bring together variqusdepartmentsand agencies related to the provision ofdrinking water in a cooperativeeffort without theneed to enforce any laws or regulations Thisprogramme is reported very successful ThePCRWR has made its modest efforts to createawarenessand to help supply good quality drinkingwater in the country Forexample.(i) Research based rainwater harvesting techniques

are practiced in the Chohstan desert wherebasically rain water is collected for rangelandmanagementbut two of our water storagepondshave been dedicated for local consumptionwherehousewivesof Dmgarhvillage are takingthis water for their drinking anddomestic needs;

(ii) Electrical Resistivity Surveyand Electncal WellLoggings are bemg conducted in various partsof the country to select the suitable sites forinstallation of tubewells to get good qualitygroundwater; and

(iii) A well equipped water quality laboratory hasbeen established in Islamabad to analyze fortydifferent parameters of drinking water requiredfor reliable drinkingwater quality analysis

Before concluding I would like to say thatdrinking water will be equivalentto oil in the nextmillennium The GOP should make its generousinvestment in the research based development andmanagement of water resources The honourableMinister may kindly consider to involve professionalresearch and monitoring organizations to ensure thatnew projects in water sector are conforming withenvironmental standards and that they arescientifically soundandeconomically viable.

My sincerethanks are to Syeda Abida Hussain,who has honoured my request and has spared hervaluable time to inaugurate this session. GeneralQazi, I feel privileged to work with you, I reallyenjoy your moral as well as financial support.

I am also thankful to Dr Din Muhammad,Dr Roshan and other organizers of Chemical Societywho reposed their confidence in the PCRWRandbrought the concept of collaborative work Mythanks are to the organizers and sponsorsof thisworkshop, I sincerely appreciate the efforts of myteam who has made its untiring effort ni make thisworkshop a successful event Dr Abdullah andMr Aslam Tahir are the key figures of my team whoreally matterto me at this moment.

Distinguished participants, ladies and gentlemen,the overall successof this workshop, lies in youractive participation.

Thankyou.

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INAUGURAL ADDRESS

Syeda Abida HussainFederalMinister for ScienceandTechnology,Governmentof Pakistan

Lt General(retd) JavedAshrafQazi, Secretary,Ministry of Science& TechnologyDr Bashir A Chandio,Chairman,PakistanCouncilof Researchin Water ResourcesProf. RoshanAhmad,Chairperson,WorkshopOrganizingCommitteeMr. Kiialil-ur-Rehmanof Water IndustryDistinguishedDelegates,Ladiesand Gentlemen’

AssaLa,n-o-Al,~iikum!

The objectives of developing country mostlyrotatearoundbetterhealth, basiceducation,shelter,ensuredsupply of food items in the market, cleanenvironmentand safedrinking water It is also verywell known that humanhealth and survival dependon use of uncontaminatedand clean water fordrmkmg and other domestic purposes As thepopulationis increasingthe world over, the demandfor water also increases.Should this augustaudienceponderupon thesefactors’), its memberswould findthat neither any item would be complete withoutwater nor prosperityand developmentof the nationin their true sense would take place wjthoutavailability of cleanwater.

As the onset of my inaugural address yougenuinelyshouldexpectthat I would say few wordsin admirationof your this collaborativeeffort So Ido! I commendthis effort. But as you know mybackgroundthat I representpoorclassesof rural andagrariancommunitiesI find little in this workshopfor them I would like to stand corrected ratherwould be pleasedif the organizationcommitteewereto tell me that its today’seffort also focuseson theuncontaminatedsupply of potablewater to the 60%of thepoor populationthat is living in rural areas Ithink similar is the case with slum areasof urbanpopulation.

Most of the rural population use to take itsdrinking water from open wells or handpumpsbutnow the salimzationof the groundwateras well asits contamination from agricultural wastes ispolluting this source.At many places,the bad odorlike that of hydrogen sulphide and salty smell isquite detectable As a result this populationhasbeencomplaining a6out spasmaticalstomach pains andothergastricdis-orders

I also drawyour attentionto the peoplewho areliving in desertslike Cholistan,Thar and Thai!, andthe hilly and sub-hilly tracts of Sindh andBalochistanwherepeoplelive on rainwaterstoredinopen ponds which is a common property for allliving beings which is being infested by allpathogens.It is a worst type of slaveryof presenttimesthat women travel miles to bring oneor twoclay pitchersfilled with wateron their heads.I thinkit will be a greatservice to Pakistanif you scientists

and industrialistscome up with a viable solution toredeem ill consequencesof our neglect and badplanning

In theagrariancommunityas that of ours, wateris also recognized a key factor for povertyalleviation I also believethat sameis the case forthe industrial society of today. It is my commonobservationthat un-guaranteedsupply of water fordomestic purposes has forced the consumers toconstructtheir undergroundwater tanks andsuctionpumpsto draw the water directly from supply lineand store it in their underground tanks. So thosewho don’t have this facility would be usurpedoftheir share I think that such type of forcedwithdrawal of drinking water may also tend sewagewater which is running parallel to drinking watersystem, to enter into drinking water lines. Myintuition alsocautionsme that such type of domesticundergroundor evenoverheadtanks neither wouldbe properlyconstructednor adequatelymaintained.

I would not feel any hesitation to say abouthouse wives who are more vulnerablethan men tothe environmentalcontaminants I strongly suggestthat this workshop should recognize the role offeminine gender and ponder upon the ways andmeans as how to bring ease and comfort to thissector in the same way or even better than malesociety ordain for themselves.All over the world,women play a crucial role in environmentalmanagement.Every one present here should beawareof the fact that in rural areas,womenare themain collectors and users of water for theirhouseholds activities They can be immediatelyaffected by degradedwater systems Unfortunatelybeing netted in the low income group, ruralcommunitiescannot relish the delicaciesof bottledwater,hencethis forum may havemoreemphasisashow to meetthe basic needsof drinking water forrural areas.

I am glad that the PakistanCouncil of Researchin Water Resourcesand the ChemicalsSociety ofPakistan have jointly organized this nationalworkshop on Quality of Drinking Water wherewater related mdustnesare also collaboratingwiththe organizersto make this workshopa success.Ihope the deliberationsof the workshopwill throw

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more light on the importantareason the useof goodquality drinking water, control of water bornediseasesand supply of low cost bottled water atpublic places. I suggest that deliberations shoulddevelopnew strategiesproviding good quality waterto every user. The Ministry of Science andTechnology has invested a moderate amount ofmoney on setting up of a well equipped waterquality laboratory in PCRWR at Islamabad. Isuggest that this forum should look into thecapabilities of the laboratory and judge themselvesas whetheror not it can be of a good use to you Ithank the PCRWR, CSP and Water Industry fortheir collaboration in this workshop and highlyappreciate the participation of scientists, engineersand industrialists,whose contributions, I am sure,would be highly valuable.

I would keenly look forward to receiving therecommendationsof this workshop Of course, afollow-up of the recommendationsis necessaryinorder to assure the implementation of the

recommendations.I would however suggest thatthey may be few and attainable If they areconvincing, and I am positive that your forum iscapableof doing so, I will be very happyto get youevery support from my government.You may liketo consider

(a) How massesshould be able to purify theirwater at abearableprice;

(b) How supply of potable water is made selfsustained,

(c) How drudgeriesof feminine classis removed;

(d) How quality of water resourcesis preserved,and

(e) Whatpublic sectorinvolvementis required.

With theseremarks,I feelgreatpleasureminauguratingthe workshopand I wishyou allsuccessin your deliberations

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VOTE OF THANKS

ProfessorRoshan AbmadChairperson,WorkshopOrganizingCommittee

SyedaAbida Hussain, FederalMinister for Science& TechnologyLt Gen. (retd) JavedAshraf Qazi, Secretary,Ministry of Science& TechnologyDr. Bashir AhmedChandio,Chairman,PakistanCouncil of Researchin WaterResourcesDr. Din Mohammad,The OrganizingSecretaryMr. Khalil-ur-Rehman,GeneralManager, HimalayaMountainValley Water(Pvt.) LimitedMembersof the OrganizingCommitteeDistinguishedGuests, Ladies andGentlemen!

Assala,’n-o-Ala,kum

Since a long time the Chemical Society ofPakistanhasbeenplanning to orgamzesometype ofworkshop, seminar or symposium in which wecould bring the chemists working in theuniversities, R&D orgamzations and theindustrialists on one platform so that differentproblemsof mutual interestcould be discussedandsolved. Some how we were unable to organize ageneral workshop on the subject of chemists -

industrialists interaction . Thanks to PakistanCouncil of Water Resourcesandsome peoplefromindustry for collaborating in organizing thisworkshopwhich is just an initial step to proceedtowardsa goal.

The needfor organizing this workshopand theobjectives havebeen summarizedm the workshopbrief I hopethat the deliberationsof this workshopwill throw somelight on importantmeasuresto betaken to improve the quality of drinking water foruseof the generalpublic We are really thankful tomadamSyedaAbida Hussainwho has sparedsomeof her valuable time to grace this occasion andinaugurate the workshop. Our sincere thanks are

also due to Lt. Gen (retd)JavedAshrafQazi for hispresence on this occasion and delivering theWellcome address. On behalf of the ChemicalSociety of Palustan I extend my gratitude toDr. BashirAhmedChandiofor collaboratingwith usin orgamzingthis workshop. We are grateful to therepresentatives of industries for participating and co-sponsoringtheworkshop My specialthanksare dueto Mr Khalil-Ur-Rehman, General ManagerHimalaya Mountain Valley Water Ltd. andMr Akram ChaughtaiService Industries Ltd. forbeing the major sponsors.The membersof theorganizingcommitteedeserve my specialthanksforworking hard to make this workshop a success.Imust acknowledgethe sincere efforts of Dr. DinMohammnad,Dr A. H. Rehan, Dr. M. Abdullah,Mr Aslam Tahir and their co-workerswho haveworkedday and night for this workshop. My thanksare also due to all other organizationswho havesponsored this workshop and finally thedistinguished participants, ladies and gentlementhankyou very much for your participation.

II

TECHNICAL PAPERS

Drinking WaterQuality and Standardizationin PakistanDr. BashirA. Chandio,Dr. M. Abdullah andM. A. Tahir

EnvironmentalPollutionandCarcinogenesisDr. S. Riaz-ud-Din

WaterBorneDiseasesDr. Khurshid Ahmed& Dr. Athar SaeedDii

Drinking WaterQuality GuidelinesValues: ChemicalandPhysicalAspectsS. Shujah & M. Jaffar

MembranesandotherProcessesto Improvethe Quality of DrinkingWaterMuhammadAshrafC/zaudhry

Separationand Speciationof Organo-PhosphorusPesticidesBasedon Hydrolysis UsingReversePhaseHPLLJasminShah,M.RasulJan andKahkeshanSaeed

Drinking WaterQuality Monitoring in the RuralAreasof RawalpindiM AslamTahir, Dr. Ba.shirA. Chandio, Dr. M. Abdullah& AbidRashid

SyntheticInorganicIon Exchangers:Efficient Scaveñgé~rsfor ToxicPollutantsin WaterSyedMoosaHasany

WaterChemistry,Quality Controlby ElectrochemiçalMethodsRiazAhmed

Nitrate Pollution in Drinking Waterand its MeasurementMuhammadManshaChaudhry, Tariq M. NaeemandAsmatuilah

Analysis of PotableWater in Dera GhaziKhanRizwanHussainandAbdulMateen

DRINKING WATER QUALITY AND STANDARDIZATION IN PAKISTAN

IntroductionWater is an absolute necessity as well as a

universalsolvent. It containsdissolvedmaterialsandsuspendedparticlesevenin its naturalstate . Thoughagriculture is its main consumer,other sectorsarealso competingandhavepotentialsto pay more Fordomestic purposes,it is requiredbetween 150 and300 1/day-capitain which groundwatermakes more

-contribution because in principle it is clean andbiologically uncontaminated,70% of drinking watersupply comes from aquifers. Presently cleandrinking water supplies are required for anestimatedpopulationof about 136 millions, out ofwhich 68% is living in rural areas.

Whereas surface water pollution comes frompathogens,chemicals,and untreatedwastes;shallowaquifer pollution comes from infiltration of wastedisposal, agro-chemicals, and other naturalpollutants. The pollution problems andenvironmentalconcernsnecessitatethat all types ofwastesshould be treated before they are disposed,however, implementation of such programs indevelopingcountriesis hinderedby cost, availabilityof resources,and the level of expertise required tooperatetheprograms.

The expertsbelieve that the water quality is amore serious problem in this country than itsquantity becauseonly about 40% of the totalpopulationis receiving potable water according toWorld Health Organization (WHO) standardsThemain quality problems related to drinking waterhaveemanatedfrom turbidity, inadequatesanitation,high bacterial load, unhygiemc water storagepractices,dischargeof civil and industrial effluentsinto water bodies, and infiltration of toxic leachatesfrom agricultural fields into aquifers. Futuredeterioration of water quality in developingcountries should be a consequenceof increasedindustrial production, rapid increasein water use,deforestation,and the destructionof natural filtersystemssuchas wetlands.

The increasein water demandproportionatetopopulation growth is common every where. Butbetter financial position and judicious resourceallocation made by the developed countries haveoffset the consequencesof population pressureonavailable water resources.They havecontrolled thepopulation growth rate, have developed newresourcesand havemanagedthe available resourcesprudently. To meet with the increasedpopulationpressureof the city of Berlin on the waterresources,an integrated management approach for waterresourceswas planned through advancedtreatmentof available resourcesto meet the stringent qualityrequirementsand to shift the treatment~towardsthesourcesof pollution to obtain an dptirnum waterresource protection. The low income countrieshowever adopt some relaxation. For example, inMorocco, maximum acceptablelevel for the totaldissolvedsolids has beenraisedfrom 1500 to 2000mg/I

The presence of organic and inorganiccompounds beyond threshold limit causes healthproblems Therefore water quality should bemaintained against diverse groups of organicchlorinated compounds, chlorophenols andpolychiorinatedbiphenyls,fluorides, pH, chlorides,total hardness,specific conductivity and sulfates.Many public water suppliesalso contain chemicalsthat cause cancer It is necessaryto detect thecarcinogenic material level in the water forpreventionpurposes Nonethelessit should be keptin mind that a total absenceof carcinogensin wateris unrealistic. Regulatingwater quality with respectto carcinogensrequiresan assessmentof the risks ofexposure.Someso calledqualitiesof drinking waterseem to be related to increased gastric cancerincidence.They are soft water (poorly mineralized,low in magnesium, and sometimes containingradioactivesubstances)and the presenceof nitrogencompounds (ammonia, nitrates, nitrites,nitrosamines).Hard, highly mineralized water is

Bashir A. Chandio, M. Abdullah and M.A. TahirPakistanCouncil of Researchin WaterResources,Islamabad

ABSTRACT: Drinking water in Pakistan is required for aboui 136 million population out of which 68%is living in rural areas Though most of the drinking water supplies are drawn from surface water andgroundwater, yet harvested rain water also makes some contribution in sandy desertsand hilly areasHowever, if the annual growth rate remains to be 2 7% then it would be very diflicult to enhance thesafe water coverageto themasseswithin next 10 yearsPresently, thewater quality is a more serious problem in this country than its volume becauseonly about40% of the total population is receiving potable water according to World Health Organization (WHO)standards The main quality problems related to drinking water have emanated from turbidity, inadequatesanitation, high bacterial load, unhygienic water storage, discharge of civil and industrial effluents intowater bodies, and inflltration of toxic leachates from agricultural Odds The PCRWR has made waterquality sampling from surface and groundwater sources around Islaniabad & Rawalpindi and hasobserved that most of the drinking water samplesof the area are contaminated with bacterial load, whilea few have high concentration of turbidity, nitrate nitrogen, sodium, iron and lead A number ofpreventive and corrective measuresto standardize and purify the drinking water are therefore discussedin this paper

14

associated with lower cancer rates. One studyassociatedhigh lead levels in water with cancersofthe stomach,kidney,and intestineand leukemia

It is very difficult to provide water for anyconsumerat 100% uncontaminatedform becauseofinhibitively high cost of such type of treatmentandpurification. Economicsplays an mfluential role inthe fmal decisionby a community with respecttothe selection of their drinking water treatmentprocess.Fortunately,for most toxic effects thereisa thresholdlevel below which no harmoccurs evenover a lifetime of exposure.It is further observedthat modernizationof water sourcesalone is not asufficient measurefor the improvement in cleanwater supplies. As usershavea strong influenceonthe quality of their drinking water, their educationand that of dwellers regardingmanagementof theirsourcesis consideredas next important factor tohelp improve the supplyof cleanwater

The quality enforcementefforts have in generalimproved the performanceof public and privatefacilities that obtamtheir drinking waterfrom lakes,rivers andstreams,treat it anddistribute it to theircustomers Martapura River of Indonesia wascontaminatedwith total coliform, Escherichiacoli,and hydrogen sulfide but when that water wastreated and chlorinatedin a residual of 1 0 mg/Lbefore it was distributedto the city, no coliform orhydrogensulfide producingbacteriaweredetected.

The distribution system itself can contribute tothis deterioration. Numerous examples ofwaterborne outbreaks have demonstrated theimportanceof the distribution systemin preventingdisease The media, environmental groups andconsumersthereforewant to seetap water commgfrom those sourcesthat are not polluted. The waterindustry, on the other hand, continues to reassurethe public that drinking water remainsas good as itwas 50 yearsago.

Groundwater is rathera main sourceof drinkingwater becauseof its presumableuncontammatablesituation.However, the analysesm the country likeUSA have showeda relatively high concentrationsof dissolvedlead, copper, iron, andzinc and traceamountsof a few organic compounds In Pakistan,thepotablegroundwateris being drawnthroughtube-wells, handpumps,open wells, springsand karezes.However, wherethe groundwateris brackishor noteasily available, the surface water is diverted tofiltration plantswhere it is allowedto remainstagnantfor a specific period to achieve partial settlmg ofsuspendedmaterials, then filtered, whereasin desertsor areasoutsideIndus basin, harvestedrainwater isusedfor drinkingpurposes

NationalDevelopmentPlansTill the year 1980, only 33% of the total

population of Pakistan had the access to theacceptabledrmking water. Hence the International

Drinking Water Supply andSanitation Decadewaslaunched in 1980 to provide potable water to allurbanpopulationand 66% of rural population.Thepriorities andtargetsof the decadewere included in

the 6th Five Year Plan. At the endof 7th Five YearPlan of the Governmentof Pakistanthe proposedcoverage of safe water supplies was extendedto75% of population,however,the abovetargetswerenot fully achieved, so that by the year 1993, only61 5% of the total country’s populationhad accessto safe drinking water. Subsequently,the 8th FiveYear Plan envisaged to provide drinking waterfacilities to 95% of population. It is envisagedthatin the next 10 years it would be very difficult toenhancethe safewater coveragefor the populationwhich is increasingat a rateof 2.7%.

Allocation of funds to thewater supply sectoraswell as to other sectorswould alwaysremainshortbecauseof economical constraints and very highpopulation growth rate. Nonethelessplanners anddecision makerswould genuinely worry as how toextend drinking water facilities to additional 3.5million per year It is fearedthat with this muchgrowth rate our constrainedeconomy may not beable to bear the consequent financial andadministrativeresponsibilitiesunlessthey are sharedor completely off loadedby the private sector. Achange in the presentpolicy is strongly required,which might rotate aroundeconomicswith a primeconcern as how to provide safe drinking waterfacilities to all consumersunder a self sustainedsystem

Drinking Water Quality AssessmentandImpacts

The quality of surface and groundwater bemgused for drinking by urban as well as ruralpopulationis ‘poor’. It hasbeenassessedthat morethan 40% end usersare not receivingpotablewateras per WHO recommendations.The analysis ofwater samples collected from Islamabad andRawalpindi by PCRWR have shown the similarresults (Tables-5 & 6). Water quality survey ofKarachi andLahore have revealedthat majority ofwater samples containedhigh bacterial load andsewageorganisms.

Almost 95% of the wells of the Karachicity andits suburbs were highly polluted bothbacteriologically andchemically; the testedsamplespossessed contain high concentration of totaldissolvedsaltsas a result of seawater intrusion intofresh water aquifers in the coastalareas.Whereasthe quality of groundwaterin Lahore is marginallypermissible, water samples collected from theadjacent localities of Lahore found to be unfit forhumanconsumption.Similar situation wasobservedfor the rural areasof NWFP, while the situationmBalochistanwasworst.

15

The World Health Organizationestimates that500 million diarrheal episodesoccur eachyear inchildrenunder five years in Asia, Africa and LatinAmerica.The extentof entericdiseasesin differentareasdependsupon the extentto which a drinkingwater is exposedto contamination.Many incidenceof typhoid, dysentery,hepatitisandotherentericandrespirator infections in many countries have beenreportedly transmittedthrough water The entry ofthese water carried human diseases into waterbodiesis to be preventedby properwater treatmentand enforcingquality standards.

In addition to above, there are many otherdiseasesrelatedto ingestionof toxic substanceslikemercury, chromium, lead, zinc, cadmium, nickel,sulphide, chlorine, ammonia,cyanide, and organicchemicals. The substances present in differentindustrial effluents in Karachi, and other citiesalongwith their levels andmaximumlimit arebrieflyas givenin Tabl-1.

Table1: WaterPollution Levelin KarachiSubstances Levelsm

IndustrialEffluentMax. Limit (mg/I)

Chromium (Cr) 200 0 5Lead(Pb) i2 0 3Mercury (Hg) - 0 004Zinc(Zo) iOO& 5Copper(Cu) 20 0 5Nickel (Ni) i 2 0 3Cadmium(Cd) - 0 03Cyanide (CN) - 0 iS

i 0Phenols -

iron (Fe) 20 4 0Oil & Grease 30 5

It canbe seenthat contentsof heavymetals arealarmingly high Their presenceis very logicalbecause textile, tanneries, and other industriesestablishedm Karachi are disposing their effluentscontaining above heavy metals without treatmentTheseeffluentseitherdumpedinto Liyari and MalirRiver or are poundedwhere from they arc leacheddown and are mixed up with groundwater Thereare also evidencesthat enrouteto their disposals,theeffluents mix up with drinking water through leakyanddamagedwater supply lines. As a result of thiscontaminationthe people of Karachi are sufferingfrom various diseases These effluents ultimatelyfind their way in the sea where marine life isaffectedadversely.

It is estimatedthat 30 percent of all reportedcases of illness and 40 percent of all deaths in

Pakistanare attnbutedto water diseasesRecentlywhen survey conductedby PCRWR showed that81996 cases of water related diseases wereregisteredonly in Basic Health Units of RawalpmdiDivision within a year.

Statusof Water TreatmentIn the areaswheregroundwateris potable,it is

being utilized directly. In semi-hilly and desert

areas,rain water is harvestedandusedafter simplecloth filtration process. In mountainous areas,springs are mainly adopted as source of supplywhich is generally goodin quality

In the areaswhere groundwateris brackishordeep, surfacewater is invariably used for drinkingpurposes after passingthrough slow sand filters toremove suspendedsolid materials. This filtered-

water is then chlorinated in treatment plants toreducethe suspendedandbacterial loadsand is thenpumpedto variousconsumersin the urbanareaslikeKarachi, Faisalabad,Rawalpindi and Islamabad Inthese treatment plants, Alum is bemg used as acoagulatingagent. Thenchemically mixed water isconveyedto a flocculationchamberuntil a thick flocof settleablematter is formed which is removedinsedimentationbasins The clear water is finallyfiltered through rapid sand filter bedsand in mostcases post chlorination is practiced. Despite theexcellent facilities for chlorination and treatmentavailable in major cities, it has beenobservedthatthe drinking water, finally suppliedto users, is yetnot “Safe” for drinking

Water Quality Standardization

The standardsfor drinking water quality arealways based on scientific research andepidemiological findings and as such provideguidance for making risk managementdecisionsrelated to the protection of public health and thepreservation of the environment. Water qualitystandardsare legal impositionsenactedby meansoflaws, regulationsor technicalprocedures,which areestablishedby countries by adapting guidelmes totheir national priorities and taking in account theirtechntcal, economical, social, cultural and politicalcharacteristicsandconstraints

Water intendedfor humanconsumptionmust befree from harmful quantitiesof microbial organismsandchemicalsubstanceswhich may posea hazardtohealth.Supply of drinking water shouldnot only besafe and free from dangersto health but also beaesthetically acceptable. The purpose of settingstandardsis to definethe quality of waterthat is safeas well as palatablefor humanconsumption.

Pakistan Council of Research in WaterResourceshadprepareda draft act on safedrinkingwater including standardsin 1993 for Pakistanandforwarded to Ministry of Scienceand Technologyfor further process The standardscontainedin theact were basically based on WHO water qualityguidelinesbut were further modified according tofmancial, environmentaland technical conditions.Thesestandardswere preparedin consultationwithwater quality experts of different relevantdepartments like PPH, Planning Commission,PCSIR ctc. The proposedwater quality standardsaie presentedin Tables2 to 4

“1

16

Table2 Bacteriolo2icalStandardsOrganisms Guideline Value

a All water inteodeil for drinkingE coli or thermotolerani coliform bacteria Must not be detectable in any 100-mi sampleb Treated water entermg the distribution systemE colt or thermotoiei-ant coliform bacteriaTotal coliform bacteria

Must not be detectable in any 100-mI sampleMust not be detectable in any 100-mi sample

C Treated water in the distribution systemE coli or therrnotoleranc coliform bacteria

Total coliform bacteria

Must not be detectable ri any 100-mi sample In the case of large supplies, where sufficientsamples are examinedMust not be present in 95% of samples taken throughout any 12 month period

SE coil is the ore precise Indicator of fecal pollution, the count of thermotolerant collforns bacteria Is an acceptable alternative. Turbidity shouldbe <1 NTU: For disinfection, with chlorine. pH preferably <8.0 and residual free chlorine should be 0 2-0 5 mg/i with mInimum 30 minutescontact time.

Table3. Standardsfor Inor2anicHealth-relatedConstituents(Thesestandardsapply to watersupplies)Constituent Unit Highest

Desirable LevelMaximum PermissibleLevel

Tome Effects

Lead mg/I 005 0 05 Children particularly susceptible to effects of lead on central nervoussystem

Mercury mg/I 0001 0001 Nesrological effectsFluoride mg/I I 0 1 5 Dental Iluorosis in children, excessive concentrative may cause

crippting_skeletal_fluorosisNitrate (NOy mg/I 45 45 Infantile methetnoglobirssma

Table4: StandardsjorAestheticand other InorganicHealth RelatedConstituentsConslatuenla Unit Hlghmt Maximum Undesirable Effects

Desirable Level Permissible LevelTurbidity N1’U 25 5 Unaesthetic decrease iii efficiency ofdisinfectionColour Pt, Co — 5 15 UnaestheticTaste aisi Odour - linobjec Uriobjec Taste and OdourTDS mg/I 500 1500 Salty taste, corrosion or instructionIron mg/I 0 1 I 0 Taste, discolorationManganese mg/I 005 05 Taste, discolorationMagnesium mg/I 30 150 Stomach disturbancesCopper mg/I - 05 I 5 Taste, corrosion of pipe & utensil tasteZinc mg/I 5 150 TasteSulfate mg/I 2(X) 4~X) Corrosion, laxative effectChloride mg/I 200 600 Taste, corrosionpH - 7 0-85 6 5-92 Taste, corrosionHardness mg/I 200 500 Corrosion or scale formationPhenolic sub Mg/I 0001 0 002 Taste

Table 5: Pollution Problemsin the WaterSupplySystemofIslamabadSr No. Year Pollutants HighestDesirable Level Above the Health Effects

(WHO) Acceptable Level(%age)

1 1989 (N03-N) 10mg/i 5 66 Disturbances in stomach arid intestine, formation of

methamnolobinaenua may cause death2 1989 Bacterial NIL 6603 Cholera, typhoid, gastro enteritis etc3 1997 Bacterial NIL 33 Cholera, typhoid, gastro enteritis etc

Table 6: Drinking Water Quality Profile (ExceedingWHOStandards)Rawalpindi District (1994)S WHONo Parameters Guide- Percentage ofSamples E,tceedlng WHO Guidelines Health Effects

linesTehsils Gujar Kahuta Murree Rawalpirsli Taxila

No of SamplesKhan29 19 23 19 26

I Bacterial Indicator-E Coli-Coliform-Non Coli

NilNil

655862

84278 9

73987

684895

53876 9

Diarrhea, Dysentery, Stomach &Intestinal disturbances etc)

Nil 862 895 87 895 7312 Nitrate (N) 0 24 I 26 3 - - II 5 Infantile methaemoglo-binaemia,

Gastrointes-tinal disturbances3 Iron (1 3 - - 34 8 - - Hemochroma-tosis4 Sodium 200 172 - - 105 - Vomiting, Muscular twitching,

Hypertension5 Manganese 0 I 862 63 2 26 1 105 100 No adverse health effects in humans were

found Undesirable taste, IncrustationPmt~an

17

RecommendationsIn order to ensurethe supply of quality water to

entire population following recommendationsaresuggested

I An umbrella water quality momtormg andevaluationcell shouldbe establishedm the centerwith its provincialbranches,

2 to establishwater quality standardsfor all sectorslike bottling water quality;

3 to selectand recommendappropriatetechnologiesfor design, construction, operation andmaintenanceof drinking water supply systems,

4 to arrangetraining programmeson water quality,andits standards;

5 to embarkon awarenessprogrammesaboutwaterquality, pollution and sanitationon Radio, TV andNewspapers;and

6 to ensure implementation of drinking waterquality standardsall overPakistan.

References

1. Abouzaid, H. and Echthabi, L (1993).“Drinking water quality and monitoring mNorth Africa: The Moroccan experience”Regional Meeting of the Society ofEcotoxicologyand EnvironmentalSafely, Rome(Italy) 26-29 Sep 1993. EnvironmentalToxicology. Hazards to the Environment andMan in theMediterraneanRegion,Vittozzi, L.(ed.) 1995. p.29-34

2. Benedek, P. (1991) “Water Quality andHealth: Review of the International DrinkingWater Supply and SamtationDecade”. WaterScienceandTechnology.23(1/3): 229-235

3 Calabrese, E.J. and Gilbert, C E (1989)“Drinking Wa~rQuality and Water TreatmentPractices Charting the Future” Safe DrinkingWater Act: Amendments, Regulations andStandards Lewis Publishers, Inc., ChelseaMichigan p 113-142

4. Clark, R. M ; Goodrich,-J-A and Wymer,L.J (1993). “Effect of the Distribution Systemon Drinking-WaterQuality”. Aqua42(1): 30-38

5. Consonery,PJ.(1995) “Pennsylvaniaprogramhelps improve drrnking water safety andquality” Water-Eng.-Manage.142(3) 30-32

6. Ghedm, E., Robidoux, L.; Handschumacher,P.; Hebrard, G. and Schmit,-J.P. (1993).“Quality of drinking water sourcesin two sub-desert Sahelian areas in north-westernSenegal”. mt.-J -Environ -Stud -Sect.-A.44(2-3): 113-130

7. Governmentof Pakistan,PlanningCommission(1983). “Water supply~Farewell to pollutedwater” In: The Sixth Five YearPlan 1983-88.Islamabad.pp 395-402.

8. Governmentof Pakistan,PlanningCommission.(1988). “Physical planning and housing” In:SeventhFive YearPlan 1988-93and PerspectivePlan1988-2(X)3.Islamabad.pp. 235-242.

9. Governmentof Pakistan,PlanningCommission.(1988). “Physical planning and housing”. In:Eighth Five YearPlan 1993-98 and PerspectivePlan1988-2003.Islamabad.pp. 287-297

10. Hamilton, K G. and Stringer, E.A. (1992).“Quality of Ground WaterUsedfor Drinking at22 Schools m Tennesseewith Supply SystemsClassifiedas Non-Community,Non-Transient.”USGSOpen-FileReport9 1-534

11. Heinzmann, B and Sarfert, F (1995). “Anintegratedwater managementconceptto ensurea safe water supply and high drinking waterquality on an ecologically sound basis”.International Conferenceon Integrated WaterResources Management, Amsterdam(Netherlands)26-29 Sep1994 IntegratedWaterResourcesManagementHosper,-SH.; Gulati,-R D., Van-Liere,-L.; Rooijackers,-RM M.(eds.)pp. 281-291.

12 Hespanholand Prost A M.E, 1994, “WaterResourcesWHO guidlmesandnationalstandardsfor reuse and water quality”, Vol 28, No. 1,GreatBritain, pp.119-124

13 Hickman,J.R, Toft, P; Armstrong,V C andMeek, M.E. (1989) “The New Guidelines forCanadian Drinking Water Quality”. In:Drinking Water Treatment Small SystemAlternatives. Pergamon Press, New Yorkp 16-25

14. Houk, V.N. (1987). “Carcinogensin DrinkingWater and Water Quality Standards” In:Pesticidesand GroundwaterA HealthConcernfor the Midwest. Proceedingsof a conferencesponsoredby the Freshwater Foundation andthe U. S. EnvironmentalProtectionAgency,StPaul, MN, October 16-17, 1986. FreshwaterFoundation,Navarre,Minnesota 1987 p.247-252

15. Kromoredjo, P. and Fujioka, R.S (1991).“Evaluating Three Simple Methods to Assessthe Microbial Quality of Drinking Water mIndonesia”. EnvironmentalToxicity and WaterQuality. 6(2): 259-270

16. Mahrnood, S. (1988) “Treatment of water fordrinking purposesfor rural and urban areas”.International Seminar of SAARC Countries,Kathmandu,Nepal

17 Mohan, S V., Nithila, P. and Reddy, S.J.(1995). “Determination of fluoride content mdrinking water and developmentof a model inrelation to some water quality parameters”.Fresenius-Environ.-Bull. 4(5): 297-302

18

ENVIRONMENTAL POLLUTION AND CARCINOGENESISS. Riaz-ud-Din

Professor& Director, NationalCentreof Excellencein Molecular BiologyUniversity of the Punjab, CanalBankRoad,ThokarNiaz Baig, Lahore-53700

ABSTRACT: The quality of life at both ihe social and individual levels would be severely restricted ifwe had to live without petroleum products, plastics, synthetic textiles, man-made mineral fibers,antibiotics and synthetic drugs or without the synthetic materials needed to produce modem electronic

devices In many ways chemicals are a basic factor in the well being and effective functioning of present

day societies They may play the role of being essential in one way and responsible for deleterious effectsunder other conditions depending upon the nature and amount present Their effects in terms ofenvironmental pollution especially related to the quality of drinking water are briefly discussed in thispaper

IntroductionAs in the case of drugs, the use of new

chemicalsimplies not only the desiredbenefitsbutalso adverse effects We are compelled tocompromisebetweencosts and benefits When thedesired and the adverse effects of the use ofchemicalsareweighed, it is pertinentto ask whetherwe really need all the new chemicals that aresynthesizedannually and whether all the 60,000-70,000 chemicals used daily in industrializedsocieties are truly essential. Some people havewonderedhow long our ecosystemcan survive andhow long the bio-system,man included,cantoleratethe doubling of the consumptionof chemicalsthatoccursevery 7-10years

In fact, all nations within the United Nationsfamily are faced today with growing problems of‘chemicalization’, and questionsof weighing risksand benefitshave becomemore and more relevant.This is because all societies have becomeincreasingly dependent on chemicals Severedamageto the ecosystemhasbeenrecognized,suchas damagedue to acid rains, the pollution of solidand water and the increasingratesof certain typesof cancer and allergies. Severechemical accidentsor epidemics,suchas thepoly-chlorinatedbiphenyls(PCBs) epidemicsin Japan,Taiwan and the USA,the dioxin accidentin Italy, the mercuryepidemicsin Iraq and Japan and the food-oil epidemic inSpain, have also emphasizedthe importance ofchemicalsafety evenin highly developedsocieties~’~

In mostEuropeanCountries, presently,45% ofthe labour force is exposed occupationally tochemicals during various stages of production,packing and transport and the specific use of’chemicalsor in the handingof chemicalwastes Onaveragesome3.5% of the labour forceis exposedtocarcinogens,but in the small industries22% of theworkers face the possibility of exposure tocarcinogensandsome46% to allergens We are stillsurroundedby facilities and apparatuscontainingPCBs. There are more than threemillion piecesofelectrical apparatus containing more than 2000tonnes of PCBs in a small country like Pakistan(GeneralStatistics)

Long ago, scientific communitieswarned aboutthe global pollution of the ecosystem, includingman ‘Chemicalizanon’ entails problems that werenot perceived by decision-makers when earlywarnings were issued, now these problems areappearing m concrete form before theadministrators,and effective solutions are urgentlyneeded. To a great extent the problems areinternational in character and, consequently, thesolutions require international action andcollaboration.

Extent of PollutionSeveralgovernmentsand political andeconomic

associations including the European EconomicCommunity, the Council of Mutual EconomicAssistance and the Organization for EconomicCooperation and Development (OECD), andinternational organizations within the UnitedNations, have undertakenspecific programmestomeet the problems caused by chemicals All theinternationalandnationalactions undertakenihus todemonstratethe need for governmentsto regulatethe growing use of ‘chemicals’ in both developedand developing countries Furthermore, anincreasingnumberof international conventionsandagreements have been compiled to preventtransboundaryeffects of chemicals.Joint action forthe monitoring of the exposure of both theecosystemand the population always plays an

-importantrole in thes~programmesandagreementsSeveral means can be applied to prevent

chemical hazards The most effective onewould beto refrain from using hazardoussubstancesand toreplace them with non-hazardousones Not allhazardousexposures,however, can be avoided,becausewe simply do not know all the possiblerisks, despiteextensivetesting programmes.So far,appropriatetoxicity testing has beendone only forabout10-25% of the chemicalsuseddaily~2~

Chlorination of water, presumably to kill itsmicrobial content,exposesthe consumerto a varietyof hazardous compounds. The variables ofestablished importance in the production ofpotentially toxic compounds are total organiccarbon, pH, ammomum and bromide ion

19

concentrationandthe qualitativecompositionof theorganicmatter. The presenceof the said impuritiesrelate to the productionof Trthalomethanessuchaschloroform, bromodichioromethane, chloro-dibromo-methaneetc.(3)

Inorganic elementssi~chas Arsenic, Brelium,Cadmium, Chromium,Nickle, Lead, SeleniumandZinc interactvery stronglyevenat tracelevels, bothwith other trace elements and with substancescommonly present m the environment Some ofthese interactions have been found to be verycomplex in their relevance to carcinogenesisSeveralof the elementshave beenshown both toenhanceand to inhibit experimentalcarcinogenesisfor tumorgrowth, dependmgon the type of tumor,tissue or carcinogenic agent administered DNAfidelity assaysof 40 metal compounds, indicatethatcationsof Hg, Be, Cd, Co, Cr, Cu, Mn, Ni and Pbincrease incorporation of nucleotide basesin thedaughterstrandof DNA that is synthesizedin vitrofrom polynucleotide templatesby microbial DNApolymerases. It has been confirmed thatcarcmogemcmetalcations causenotable increasesmthe mis-incorporation of all four nucleotides byDNA polymerases in vitro, whereas non-carcinogenicmetalsdo notchangethe fidelity (4)~

CarcinogenesisDNA Reactive compoundshave proved to be

important in carcinogenesis.Damage to DNA canresult in mutagenesis, which is mvolved incarcinogenesis~4~.Early experimentersfound thatcarcmogenesisinvolved two distinct stages, forwhich the terms ‘initiation’ and ‘promotion’ werecoined. Nowadays, initiation is generally equatedwith mutagenesis,andpromotersarethought to alterthe balancebetweengrowth of initiated andnormalcells in favour of initiated cells, the number ofwhich increase sufficiently to make probable asecondmutagemcprocessthat confersmalignancy.Suchsecondmutationscanbe inducedby mutagernccarcinogens.

Few studies were done on reactions of DNAbefore the advent of the Watson-Crick model ofDNA and its replication. Although DNA wasrecognizedas the geneticmaterial, its possible roleas a receptorof carcmogenswas confinedto theirbinding by non-covalent van der Waals forces.Alkylating agentsattack nucleophthcbasic atoms,i.e , the ring-mtrogenatoms of DNA bases, thusaccountingfor the resultantchangein the ultravioletabsorption spectrum of DNA. Using dimethylsulfate it was found, that N7 of guanmewas themost reactiveatom and the more basic groups ofadenineand cytosine were m fact less reactive inDNA. The methylationproductsof the latter basicgroupswere1-methyladenme& 3-methylcytosine.~5~

Regarding the analogy between the action ofAlkylating agentsandof acid on DNA, it was notsurprising to find that depurination of certain

alkylpurines, i.e. 3- and 7-substituteddeoxyribonucleotides,is much more facile at neutralpH than that of the parentpurines, as found first for7-methylguanine.This would potentiatefission ofthe deoxyribose-phosphatechain of the DNAmacromolecule, thus accounting for the“radiomimetic” nature of methylating, and otheraliphatic, alkylating agents The methylation ofDNA per se was also deduced to be a potentialsource of cytotoxicity, since 3-methylpurines areremoved from DNA by repair systems andalkylation of DNA at N3 of adenmeor guamneisthereforea significant interferencewith the functionof the DNA template

A further interesting feature of thedestabilization of the imidazole ring of guaninenucleotideby alkylation at N7 is the alkali catalysedring fission to yield a 2,3-diamino-4-oxy-5-formamtdopyrimidin&5~This type of reaction hasrecently sprung into prominencewith the findingsthat not only does ionizing radiation (actionthroughOH radicals in aqueousmedia) attackthe imidazolering of guanme in DNA but all DNA samplescontain comparatively large amounts of 8-oxypurines and the ring-openedguanine derivative.Evenmore notable is the fmdmg that DNA frombreasttumors contains 8-17 times the amountsincontrol DNA, i e., over 106 moleculesper humandiploid genomecontent, and the highest observedextent of chemical modification of DNA so farfound~.

Early work in which biological action wascorrelatedwith chemical damageto DNA showedclearly that cells were not inactivatedreproduciblyby the very low doses that induced single lethallesions,suchascross-linksin DNA. Thus, with 325~

labelled mustardgas, the dose requiredto give onelethal hit in the genome (6x106 DNA-P) ofEscherichiacoli was about 72 molecules of theproduct of difunctional alkylation, di (guanin-7-yl)ethyl sulfide,whereasa singlecross-linkof this typesufficed to inactivatea double-strandedDNA phageT7, both inter- and intrastrandcross-links beinglethal. Thisdiscrepancywasexplamedby the abilityof the bacterialcell to removethe cross-linksby anenzymicrepair process;the mono-alkylguaninewasnot removed,showing it to be relatively non-lethal.A sensitive strain was unable to remove the cross-links, as shown chemcially or physiocochemically,when interestrand cross-linkage doubled themolecular weight of the alkali-denaturedchromosome. During repair, DNA synthesis wastemporarily halted. “Bulky” adducts, such as N2-aralkylguamne induced by 7-bromoethylbenz [a]anthracene,also proved to be effecrtive lethallesions in T7 phage, i e. block the actionof DNApolymerase~5~.

The suspendedlethal lesion, 3-methylademne,and the promutagemc06-methylguaninewere also

-I

20

found to be removedby repair enzymes,the lethal3-methyladeninewasremovedmore rapidly. It wastherefore surprising that an N-glycosylase enzymeisolated from E.coli was reportedto remove bothtypes of base. It was shown subsequentlythat O6~

methylguanine in DNA is repaired throughdemethylation,with transferof the methyl group toa cystemyl residue of an alkyl acceptor protein,which is therebyinactivated

Whereasmousecells, apart from liver, are notas efficient as E coli in repairing06-methylguanme,human cells appear to be generally proficient,although some variation was found betweenindividuals. All mammaliancells are proficient inremovalof 3-methyladenine

The “bulky” adducts and cross-links areremoved by endonucleasesrelated to those firstdetectedby their ability to repair ultraviolet light-inducedpyrimidine dimmer. The importantpoint toemerge from these studies is that, although thecross-links are completely removedfrom DNA ofE coli, mammaliancells effect incomplete removaland appear to survive by the ability of DNApolymeraseto “by-pass” potentially lethal lesions.Although the details of the mechanisms areuncertain,one outcomeis that mutationsare inducedin which adenineis the basepreferentially insertedoppositethe “non-instructional” lesion Since most“bulky” adducts are guamne derivatives, theresulting mutations are most likely, but notinevitably, GC-TA transversion. Adeninederivativesare also induced,notably by metabolized7,l2-dimethylbenz[a] anthracene,resulting in AT-

TA transversions.Thus, aralkylating agents inducetransversionswith methylating agents, which giveGC-AT transitions.

ConclusionsTwo base substitutions predominate GC-At

transitions and GC-TA transversions, whichexperimentally would reflect the action ofmethylatmgagents through 06-methylguanineor ofaralkylatingagentsthroughN2-aralkylguanines.Thecurrent consensusis that the transitions are mostprobably due to hydrolysis of cytosme of 5-methylcytosinein DNA. Hydrolysis of the latter tothymine would be more difficult to repasr, and itspredominanceis supportedby the observationsthatthe majority of transitions occur at CpdG“hotspots”. Deficiency in repair would be expectedto enhanceinitiation of tumours, and that was thecase for patients with the rare inherited diseasexerodermápigmentosium(4),

References

1. Rantanen,J. (1984), IARC PublicationNo. 59,p 13-15.

2 IARC Monographs,Vol. 58, (1993)

3 IARC Monographs,Vol. 52, (1991)

4 Riazuddin, S (1984) “RepairableRevisions in

Microorganisms”p 149-186

5. Lawley, P D (1994), IARC Publication No.125, p. 3-22

21

WATER BORNE DISEASESKhurshid Aluned

ConsultantPathologist,KRL HospitalandScientistEmeritusNational Instituteof Health, Islamabad

Athar SaeedDiiJointExecutiveDirector and Chief Public HealthDivision

National Instituteof Health, Islamabad

ABSTRACT Poor quality drinking water is the major factor in spreading of bacterial, viral ~ndparasitic diseases amongst human beings and other domesriL as well as wild animals

IntroductionWater is a basic, indeedanabsoluterequirement

for the survival of human race, potable and safedrinking water being essentialfor the health andwell being of the community

Over 70 percent of body mass in an averagenormal human adult consistsof water This means50 liters of water in a 70 Kg man Without adequateamount of water in the internal body environment,vital metabolic functions will be - seriouslyjeopardized in the humanorganism

Unfortunately clean water for humanconsumptionis fast becominga costly anddifficult-to-obtain commodity available only to the luckyfew, particularly in the third world countrieswherea major sectionof the populationin the rural as wellas urban communities is without clean drinkingwater

Water supplies,even in reasonablygood set-upsare frequently subjectto contaminationby biologicaland to a lesserextentby chemicalimpurities whichare responsiblefor a variety of illnessesin man. Thecausal agents of these illnesses commonlytransmitted through drinking water includepathogenic organisms like bacteria, viruses,protozoaandparasitic worms on the onehand andsomepoisonouschemicalsubstanceson the other

Table 1 lists major diseases which aretransmittedthroughthe use of water with particularreferenceto their prevalencein our country.

Table1. Diseasesdue to Microbial Contamiruition

Bacterial Viral ParasiticSalmonellosis Hepatitis A AmoebiasisShigellosis HepatitisE GiardiasisCholera Helminthiasis

Round wormPin wormGuinaewormAmoebicnieningoencephalitis

Lead poisoning (Plumbism) is the one of themost important and the best known water bornediseasescausedby a chemical poison followed byfluorosis,dentalcariesandothers.

A brief account of microbiological andepidemiologicalaspectsof someof thesediseasesisgiven in the following paragraphs

SalmonellosisA broad term which is applied to a disease

complex causedby infection with any of the morethan 2200 serotypesof Salmonellae,which are gramnegativemotile rods inhabiting human and animalintestine Clinically and microbiologically,salmonella infection falls into two major patterns(Keusch 1991).I Typhoidal Typhoidor EntericFever2 Non-typhoidal Entero-colitis

Eachof theseclinical entities is associatedwithspecific salmonella serotypes and in both, theorganisms are transmitted by ingestion ofcontaminatedfood and water

Typhoid (Enteric Fever)An acute febrile illness causedby S. typhi or S

paratyphi-A & B and characterizedby the invasionof blood streamby salmonellae.Large outbreaksoftyphoid are usually water borne while small outbreaks and sporadiccasesare usually food borne.Incubationperiod varies from 10-14 days Man isthe only reservoir and source of infection, as noanimal is known to suffer from typhoid feverMajority of casescanbe tracedto a humancarrier.A patient or a carrier excretesviable salmonellaeinstool which contaminatefood andwater,whentakenby another individual, infection is promptlytransmitted. On reaching the intestine, organismsinvade the mononuclearphagocytesin the gut wallthrough which they are carried to the blood streamvia the lymphatics causinga sustainedbacteraemiaandsepticaemiaresulting in persistentfever

Clinically, typhoid is characterizedby a slow,step-laddertype of rise in temperatureover a periodof 7-10 days. If untreatedthe fever lasts for 4-8weeksandmay leadto haemorrhageand perforationof the gut wall Specific treatmentpromptly cutsshort the course of the disease and preventscomplications.If untreated,typhoid mortality maybe as high as 10-15%. Specific Therapy reducesthemortality to less than 1 % Typhoid is oneof the two

22

treatable causes of fever commonly seen in ourcountry, theotherone beingmalaria.

A proportion of casesof typhoid may becomecarriers Temporary carriers (about 10%) excretesalmonellaein their faecesfor upto one year, 2-5%may become long term/permanent carriers,excreting the organisms intermittently orcontinuouslyover prolongedperiods.

Prevention& ControlCleanand potabledrinking water is the mainstay

of prevention and control of typhoid Carriersshouldneverbe allowedto work as food handlers

EnterocolitisEnterocolitis, commonly termed as

gastroentritis,is by far the commonestmanifestationof salmonellainfection and is causedby serotypesother than S typhi and paratyphi, S typhimuriumbeing the commonestand the best known Theillness hasanincubationperiodof 4- 48 hours andischaracterizedby diarrhea,vomiting, colic and feverIn the vast majority of cases,it is a self-limitingconditionwith completerecoveryin 3-5 days As arule, salmonellaeremain confined to the intestinaltract Unlike typhoid, these, serotypesalso infectanimalsandpoultry which are frequently the sourceof humaninfection.

ShigellosisShigellosisor bacillary dysenteryis one of the

commonestcausesof bloody diarrheain this countryand is causedby any of the four speciesof Shigella,which are gramnegativenon-motilerods andwhich,like typhoid salmonellae, are exclusively humanpathogens, and the infection remains confined toGIT Highly communicablefrom personto personwith a low infective dose (1000 organismsonly),shigella dysenteryhas an incubationperiod of 1-2days After ingestionof contaminatedwater or foodthere is suddenonset of diarrheawith mucous andblood, fever and abdominal colic 50% of thepatientsrecoverspontaneouslyin 2-5 days.

Shigellae are excreted in the faeces for 2-3weeks.Chronic carriersarerare andthe mortality isless than 1 %

CholeraPredominantlyas Asian diseasewith pandemic

spread,cholera is characterizedby explosive onsetof profuse watery diarrheawith rice water stoolsand vomiting leading to rapid dehydration andcirculatory collapse If untreated, death occurswithin a few hoursin morethan 50% cases.

Vibrio choleraor commabacillus,the etiologicalagentof cholera, is a highly motile gram negativecurved rod which infects the human intestine andproducesa powerfulcholeratoxin. This toxin causesmassive hyper-secretionof water and electrolytesresulting in profusewatery diarrheawith fluid lossof upto 30 liters per 24 hours

EpidemiologySource is almost always faecal contaminationof

water from an infected person, vibrios survive inwater for upto threeweeks Since gastric acidity islethal to the vibrios, a high infective dose (upto 10)is requiredand only 1- 5% of thoseexposedbecomeill However, if gastric acidity is buffered by aheavy meal, a lesser infective dose will initiateillness In betweenoutbreaksand sporadic cases,Vibrio cholerae is maintained by continuoustransmissionthroughsubclinicalinfections

Management & PreventionWith modern approachesto management,no

patient of cholera should die if dehydrationtherapyis startedin time along with appropriateantibiotics.Vibrio cholerae remains fully susceptible todoxycycline and nalidixic acid Sanitary measuresespecially careful attention to water supply willeffectively control the spread of cholera in thecommunity

Water Borne Viral HepatitisAmong the several different forms of viral

hepatitisknown sofar (namedalphabeticallyfrom Ato G), only the causativeagentsof Hepatitis A andE are transmitted through the faecal-oral route.Whereasdrinking water is the major vehicle ofinfection in Hepatitis E, water bone injection ofHepatitis A is notuncommon

Hepatitis A and E are the commonestcausesofjaundicein this country Hepatitis A, both overt andsubclinical, is extremelycommon,by the ageof 15,95% of the populationbecomesimmune. Both theviruses are excretedin stools of infected individualsand both produce essentially a benign and self-limiting infection with no chronic sequelaeHowever there are also significant differencesbetweenthe two as given in Table2

Table2 ImportantIndicesofHepatitusA &HepatitisE

Indices HepatitusA HepatitusE

IncubationPeriod

15-45 days(Ave 23 days)

3-9 weeks(Ave 6 weeks)

Age incidence Max upto 15 yrs Max 15-45 years

Out breaks Moderate, personto person spread

Large epidemicsusually water-borne

Mortality < 0 1 % Upto 3%, 20-40%in pregnancy

Immunity Life long Undetermined

Householdcontacts

Attack rate 10 -

20%< 3 %

There was a large out break of water-borneHepatitisE in two sectorsof Islamabadin 1993-94which affected3700 inhabitants(almost 10% of the

23

population) in thesesectors(Dil 1994) Serologicaland EM confirmationwasmadein selectedcases.

ParasiticInfectionsSome of the common parasitic infections in

which contaminateddrrnking water plays a majorrole in transmission, include Amoebiasis (amoebicdysentery),Giardiasisand the commonround worminfestation(Ascariasis)

AmoebiasisPrimarily an intestinal infection by a Protozoan,

Entamoebahistolytica, it can manifest itself asAmoebic Dysentery (Intestinal Amoebiasis)or asAmoebic Hepatitisand liver abscess(Extra-intestinalAmoebiasis).

Asymptomatic carriers usually pass severalmillion amoebiccysts daily in their stool which aretransmitted through contaminatedwater or foodamongthe generalpopulation

According to conservativeWHO estimates,10%population of the world at large and 50% in thedevelopingcountriessuffers from amoebiasiswhichdirectly resultsin 40 million disablinginfections andabout 45000 deaths annually mostly in the thirdworld countries

GiardiasisGiardialamblia, a common intestinalprotozoan,

is probablythe singlemost frequentcauseof water-borne out breaks of diarrheaespecially in youngchildren More than 20% population of thedeveloping world is infected, with faecallycontaminatedwater containingcysts being the majorsourceof infection

AscariasisAscaris lumbricoides is the largestround worm

which afflicts man and which has a world widedistribution Prevalencemay be as much as 50% insome communitiesand most susceptiblesection ofthe populationappearto be children of pre-schooland earlyschoolage.

Eachfemale roundworm producesupto 200,000eggs per day which are passedin stool When thelarvae havedevelopedin theseeggs in 10-50 days,they are highly infectivewhen ingested in water orgreen vegetables.Drinking boiled water, handwashing and avoiding raw vegetablesor washingthem before eating will effectively break the chainof transmission.

Lead Poisoning - PlumbismLead is the commonestpoisonousmetal which

may gain entry into water supplies Major source isthe exhaust fumes from automobiles followed byleadpipesusedin the past for water distributionandleadedpaints.

Exhaust fumes from leaded petrol are slowlydepositedon the soil and on the surface of largebodies of water (lakesand dams) from where themetal gradually finds its way into drinking water.Ingestedlead is absorbedthroughGIT andproducesa cumulativeeffect over prolongedperiodsresultingin typical featuresof Plmbismlike wrist drop and acharacteristicblue line at the junction of gums andteeth

In a recentstudy (Hafeez& Malik, 1996), 90%of pre-schoolchildren agedbetween 1 and 5 werefound to have blood levels above the acceptablelimit of 10 ~tg/dl1 Besidesdrinking water, pica was

found to be a common source of increasedleadlevels in thesechildren

References

1 Benenson, A.S ed. (1980). “Control ofCommunicable Diseases in Man” 8th ed.AmericanPublic Health Association.

2 Dil, AS (1994) “PersonalCommunication”

3. Hafeez, A & Malik, Q.U (1996) “Blood LeadLevels n Pre-school Children in Rawalpmth”JPMA, 46, 272, 1996.

4. Jawetz,E, Melnick, J.L. & Adelberg, E A. eds(1987) “Review of Medical Microbiology” 17thed. Appleton& Lange

5 Keusch, G T (1962). “Harrison’s Principles ofInternal Medicme”. Vol 1 12th ed. McGraw-Hill

6. Piekarski, G. (1962) “Medical Parasitology”.BayerAG

7 Schroeder,S.A., Krupp, M.A.; Tierney, L.M.& McPhee, S J eds. (1991) “Current MedicalDiagnosis& Treatment” 30th ed. Prentice-Hall.

24

DRINKING WATER QUALITY GUIDELINE VALUES CHEMICAL ANDPHYSICAL ASPECTS

S. ShujahandM. JaffarDepartmentOf Chemistry,Quaid-e-AzamUniversity, Islamabad(45320), Pakistan

ABSTRACT: The assessmeni of toxicity of drinking-water contaminants can be made relIably throughquality guideline values based on drinking-water consumption as a function of body weight, ingestion andindirect exposure, health risk evaluation and tolerable daily intake limits Using existing internationalmethodology, procedure is defined for obtaining guideline values, for inorgamc, organic, pesticide anddisinfectant contaminants in drinking-water Tabulated data on these contaminants are made available fordissemination to environmental researchers engaged in water quality assessment or regulation

IntroductionWater is a vital naturalresource It covers about

80% of earth’s surface and plays a key role insustaininglife on this planet. About 2 5 % of thetotal 1,360 million km3 water on earthis fresh,mostof it lockedup in deepaquifersor frozen in ice capsand only 33,400mi of water is available fordrinking, agricultural, domestic and industrialpurposes.In the pastyearsgrowth of populationandrapid industrialization not only raised the demandfor morewater but haveplayedan instrumentalrolein deteriorating the quality of aquifers. This hasresultedin a rise of water bornediseases. Over70% of the world’s population depends on water fromuncertain sourceswhich may be contaminatedwithindustrialas well as domesticwastes It is estimatedthat, due to the anticipateddoubling of the worldpopulation as well as further industrialization andgrowth in the sizeand densityof our urbancenters,the amountof freshwater availableper personwilldeclineby 24 % in theyear 20001

The unique solvent propertiesof water not onlyprovide a base for different biological and phsico-chemical processesbut also make it susceptibletocontaminants arising from various anthropogenicand natural activities, consequently,pollutants fromindustrial processes, municipal waste andagricultural run-off enter the aquaticsystemdirectlyor through different pathways, they change thephysico-chemicalandbiological propertiesof waterand render it unfit for human consumption Thewater pollutants can be organic including oxygendemandingwasteslike domesticandanimal sewage,biodegradableorganiccompounds,wastesfrom foodprocessingplants, meat-packingplants, slaughter-houses,paperand pulpmills, tanneriesetc.,disease-causingagentsincluding pathogenicmicroorganisms(like virusesand bacteriaresponsiblefor dangerouswater-borne diseases like cholera, typhoid,dysentery,polio and hepatitis), synthetic organiccompounds like pesticides, detergents, foodadditives, pharmaceuticals, insecticides, paints,synthetic fibers, elastomers,solvents, plasticizers,plastic andoil or inorganiccompnsingof metals ormetal compounds,trace elements, mineral acids,

inorganic salts, cyanides, sulphates, nitratespolyphosphateand organometalhccompounds

Industrial wastesare the main culprit for waterpollution in areasclose to Industrial zones Thewaste water generatedby industries like textile,pharmaceutical,tanneries,plastic andrubber,metaland electroplating, glass and ceramics, chemical,soaps,detergents,paints, pesticides,food processingand steel mills contain large amounts of organicpollutants, heavy metals, suspendedand dissolvedsolids. Manufacturing industries also generate avariety of solid or semi-solidwaste having toxicorganic and inorganic constituents Leaching ofhazardous materials from solid waste (garbage,rubbish, pathological andagriculturalwaste) dumpsalsoposethreatto the nearbywater bodies. In urbanareasthe seepageof sewerageinto the drinking-waterdistribution systemsis also of utmostconcern

Theproblemof water pollution dueto dischargesof domestic and industrial wastes into aquaticsystemshas already become a serious problem inPakistan24.Nearly 90% of Pakistan’spopulationisexposedto unsafedrinking water According to anearlyestimateconsumptionof sewagecontaminatedwater would account for 30 % of all reporteddiseasesand40 % of all deathsin Pakistan5 In 1980the WHO recorded 3150 cases of waterbornediseasesper million population6, another reportshowedthat in 1981 therewereat least50,000 casesof typhoid andparatyphoidfeversalonein Pakistan7,accordingto anotherestimatethe annual numberofcasesof waterborneinfections in Pakistanmay becloseto 3 million8 The groundwatersare alsounderpollution stress,especiallynear industrialareas9.

Improper waste disposal practices resulting inthe deathof humansthroughcontaminationof watersystemshas raisedworldwide concern. In order towardoff the humanhealth against the ill effects ofcontaminatedwaters, there is a dire need forestablishingquality guideline valuefor the physical,microbiological and chemical safety of drinkingwater.The presentattemptreflectsthis aspect.NecessaryBackground Information

Following information is critical for monitoringand impact assessmentstudies on water quality.Only brief outline in eachcase is provided.

25

Sourcesof Daily IntakeInhalation, direct ingestion, dermal contact

during bathmgand showeringRisk Assessment

Studieson human population, toxicity studiesonlab animals, studies on dose - responserelationship,expertjudgment

Background data for Developing guidelinesPublished reports from open literature,

governmentreports; unpublishedproprietary data,existing international information, previous riskassessmentstudies(Government& NGOs), Worldauthority data such as programme on chemicalsafety IPCS (International Health criteria), EHC(Environmental Health criteria), IARC(InternationalAgency for Researchon Cancer),andFAQ/WHO expertcommittees,etc.

Water Consumption and Body Weight CriterionWater consumption data are limited,

Consumptionof water varieswith climate, physicalactivity andculture,and temperature,

For potentially hazardouschemicals,a daily percapitaconsumptionof 2L by a person weighing 60kg is assumed,

For high intakes (e g for infants and children)higherexposureis expected,

Irreversible effects (social, public health) aremoredrasticin youngage,

Guidelinesfor 10kg child (1L/day)or 5kg infant(consuming0 75 L/day) are different

TheTolerable Daily Intake (TDI)This is definedas NOAEL and LOAEL given as

underalongwith a few otherdefinitions• NOAEL highest concentrationof a substance

that causesno detectableadversehealtheffect,• LOAEL: Lowest observedconcentrationof a

substanceat which thereis a detectableadversehealtheffect, and

• UF uncertainty factor, for interspeciesvariation,usually 1-10

ATDI = NOAEL (or LOAEL’)

Here,L~\TDI = f (amount of substancemg kg-l,~igkg-i of body weight that can be ingesteddailyover a lifetime without appreciablehealthrisk).FromATDI, we obtamGV (guidelinevalue)

GV= TDIxWxP

WhereW = 60kg body weight forchildren, 5kg for infants, Pallocated to drinkmg waterconsumptionof drmking-waterfor children,0 75L for mfants)

In view of all this, Joint FAO / WHO ExpertCommittee on Food Additives (JECFA) and JomtFAO/WHO Meeting on PesticideResidues(JMPR)

havedevelopedacceptabledensity intake ADIs forwater Data relevant to water quality criteria arenow summarizedin Tables-i to 8

Table Iconcentra

Chemical

Chemicalsnotofhealthsignificanceattions normally foundin drinking water

Remarksasbestos It is unnecessary to recommend a health basedsilver guideline value For these compounds because they aretits not hazardous to human health at concentrations

normally found in drinking water

Table2: Variousparamertersand constituentsresponsiblefor waterpollution

Physical parametersInorganic constituents

Colour, Hardness, pH, Taste 8c odour, TDS,TurbidityAl, NH~,Sb, As, Asbestos, Ba, Be. B, Cd, Cl,, Cr,Cu, CN, F, H~s,Fe, Pb, Mn, Hg, Mo, Ni, NO~,N0~,DO, Se, Ag, Na, SO~,Sn, U, Zn

Organic Consiiiuents(cunsequetice oldisinfection)

Carbon tetrachloride. dichloromethane, dichloroethane,trtchloroeiharic, vinyl chloride, diclsloroethane,tn & tetracliloroethene, henzene, loluene, xylene,styrene,polynuclear aronsatic hydrocarbons,chlorobenzenes, pthalates, arnides, etc

Pesticides &herbicides(agricultural run-off)

numerous (as many as 30)

Dismufectants Chloramtues chlorine, Chlorates, Iodine, Bromates,Clilorophenols, formaldehydes, trihalomethanes,Chloro acetone, halogenated acetonitriles

RadiologicalLontaminants

(various

Table4: Chemicalsofhealth significanceindrinking water

anitmony 0 005 (P)

arsentc 0 Oi (P)bartum 0 7berylitum NAD

boron 03cadmtum 0 003chromium 0 05 (P)copper 2 (P)cyanide 0 07fluoride I 5Lead 001Manganese 0 5 (P)Mercury (total) 0 001moly~ienum 0 07ntckel 0 02nttrate(as NO

1’) 50nttrtte (as NO~) 3(P)selenium 0 01uranium NAD

Table3 Bacteriologicalquality of drinking waterOrganisms Guideline valueAll water ititended for drinkingE coli or therniotolerant Must not be detected in 100 ml samplecoliform hacieriaTreated water entering thedistribution system Must not be detected in 100 ml sampleF colt or therinotolenant Must not be detected in 100 ml samplecoliforin bacteriaTotal colmform bacteria

Treated waler in the distributionsystem Must tiol be detected in 100 ml sampleE coli or thermotolerant Must not be detected in 00 ml sample Incolilorm bacteria the case of large supplies, where sufficientTotal coliform bacteria samples are examined, must not be present in

95 % of samples taken throughout any 12-month period

UF

A InorgamcconstituentsGwdelme value tm&L)

C

adult, 10 kg for= fraction of TDIand C = daily

(2L for adults, 1L

26

B: OrganicConstituents

Organiccompound Guideline value (~ig/L)a. Chlorinated alkanes

Carbontetrachioride 2Dichloromethane 201,1-dichloroethane NAD1 ,2-dichloroethane 30i,l,1-trichloroethane 2000 (P)

b. ChlonnatedethenesVinyl chloride 5i , 1-dichloroethene 30i,2-dichloroethene 50trichloroethene 70 (P)tetrachloroethene 40

c. Aromatic hydrocarbonsbenzene iOtoluene 700xylenes 500ethylbenzene 300styrene 20benzo[a]pyrene 0 7

d. Chlormatedbenzenesmonochlorobenzene 3001 ,2-dichlorobenzene 10001 ,3-dichlorobenzene NAD1 ,4-dichlorobenzene 300trichlorobenzene (total) 20

e. MiscellaneousorgamcsDi(2-ethyihexy!)adipate 80Di(2-ethylhexyl)- phthalate 8Acrylamide 0 5Epichlorohydrin 0 4 (P)Hexachiorobutadiene 0 6Edetic acid (EDTA) 200 (P)Nitrilorriacetic acid

200

Dialkyltins NADTributytin oxide 2

C: Pesticides

Pesticide Guideline vaiue(~.igIlitre)

20100 0323050 2

alachloraldicarbaldnn/dieldrinatrazinebentazonecarbofuranchlordanechiorotoluron 30DDT 21 ,2-dibromo-3-chloropropane 12,4-D 301 ,2-dichloro-propane 20 (P)i,3-dichloro- propane NAD1 ,3-dichloro- propene ethylene 20dibromideheptachior andheptachior epoxide 0 03Hexachloro-benzeneIsqproturon ~9_______________

Lindane 2MCPA 2methoxychlor 20metolachlor 10molinate 6p~ndimethalin 20p~ntachlorophenol 9 (P)p~rrnethrin 20

propanil 20pyridate 100simazine 2trifluralin 20chlorophenoxy herbicides other than2,4-D andMCPA2,4-DB 90dichloroprop 100fenoprop 9MCPB NADmecoprop 102,4,5-T .

9

D. Disinfectantsanddisinfectantby-products

Dismfectants Guideline value (mg/L)monochioramine 3di- and trichloramine 5chionne dioxide not establishediodine NADbromate 25 (P)chlorate NADchlorite 200 (P)

chloro henols2-chlorophenol NAD2,4-dichiorophenol NAD2,4,6-tnchlorophenol 200formaldehyde 900MX NAD

trthalom ethanesbromoform 100dibromochioro-methane 100bromodichloro-metane 60chloroform 200

chlorinatedaceticacidsmonochioro-aceticacid NADdichloroacetic acid 50 (P)trichloroaceticacid 100 (P)

chioral hydrate(trichloroacet-aldehyde) 10 (P)chioroacetone NAD

halogenatedacetonitrilesdichloroaceto-nitrile 90 (P)dibromoaceto-nitrile 100 (P)bromochloro-acetonitnle NADtrichloroaceto-nitrile 1 (P)cyanogenchlonde(as CN) 70chloropicrin NAD

(P) Provisional guidelinevalueNAD No adequatedatato permitrecommendationof a

health-basedguidelinevalue

Table5. Maximumallowable concentrationofvarious toxic elementsand bacteriologicalquality of

drinkingwater

Lead (as Pb) 0 1 mg/ISelenium(asSe) 0 05 mg/IArsenic(as As) 0 2 mg/IChromium (as Cr Hexaalent) 0 05 mg/ICyanide(as CN) 0 01 mg/IFluorides 1 0-1 5 mg(max

0 5 mg/I (minimummust)

Nitrates 50-100mg/lBacteriologicalQuality a) Untreatedwater

MPN = 10 -20b) TreatedwaterMPN=<i

* MPN Most probable No , index of coliform micro-organismcontamination

27

I Screeningvalue (Bg/litre)j grossalpha activity 0 I

[g~osi betaactivity 1

Table7: Substancesandparametersin drinking-water thatmaygive rise to complatntsfrom

consumers

Parameter Levels likely togive nseto

consumercomplainis

Reasonsfor cosaumercomplaiols

- PhyslealparamrhrsColour 15 TCU appearance

tasteand odour - shouldbe acceptable

Temperature - shouldbe acceptable

Turbidity 5 NTU apperance,for eftectiveterminal disinfeciion,medianturbidity �1NTU,singlesample�5NTIJ

b InorganiceonstituenSAluminium 0 2 mg/L depositions,discolorationAmmonia 1 5 mg/L odourand tastechloride 250mg/L taste,corrosion

copper I mg/L staining of laundry andsanitaryware(health-basedprovisionalguideline_value_2_mg/L)

hardness - highhardness scaledeposition,scumformationlow hardnesspossiblecorrosion

hydrogensulfide 0 05 mg/L odourandtaste

iron 0 3 mg/L stainingof laundry andsanitaryware

manganese 0 1 mg/L staining of laundry andsanitaryware(health-basedprovisionalguidelinevalue 05 mg/L)

dissolvedoxygen - indirecteffects

pH - low pH corrosion

sodium ~00mg/L taste

sulfate 250mg/L taste,corrosion

total dissolvedsolids 1000 mg/L tastezinc 3 mg/L appearance,taste

OrganicconstitueMstoluene 24-170jig/L odour, taste(health-based

guidelmevalue 700 tg/L)

xylene 20-1800~ig/L odour, taste(health-basedguideline value 500 ig/L)

ethylbenzene 2-200t.tg/L odour, taste(health-basedguidelinevalue300jsg/L)

styrene 4-2600t.tg/L odour, taste(health-basedguideline_value_20_.ig/L)

monochloro-benzene 10-120pig/L odour, taste(health-basedguideline value300jtg/L)

I ,2-dichloro-benzene 1-10 sgIL odour, taste(health-basedguideline value 1000~ig/L)

1 ,4-dichloro-benzene 0 3-30 ~tg/L odour, taste(health-basedguideline value 300~sg/L)

tnchlorobenzene(total)

5-50 pg/L odour, taste(health-basedguideline value 20Rg/L)

syntheticdetergents - foaming, taste,odour

Disinfectantsanddisinfectantby-productschlorine 600-1000 ~ig/L tasteand odour(health-

basedguideline value5mg/L)

chlorophenols

[~~hlorophenol 0 1-10 ~ig/L taste,odour

2,4-dichlorophenol 0 3-40 pg/L tasle,odour

2,4,6-trichloro-phenol 2-300 jig/L taste,odour(health-basedguideline_value_200_pg/L)

TCU truecolourunit

NTU nephelometncturbidity unit

Table8: Drinking waterspecjfications~’°~Parameter Permissiblelevela ExcessivelevelsTotalsolids 500 mg/I 1500mg/I

Colour S units 50 units

Turbidity 5 units 25 units

Taste Unobjectionable -------

Odour Unobjectionable —-----

Iron (Fe) 0 3 mg/I 1 0 mg/I

Manganese(Mn) 0 1 mg/I 0 5 mg/I

Copper(Cu) I 0 mg/I 1 5 mg/IZinc(Zn) 5 0 mg/I 15 mg/I

Calcium(Ca) 75 mg/I 200 mg/I

Magnesium(Mg) 50mg/I 150 mg/I

5ulphate(5O~’) 200 mg/I 400mg/I

Chloride(CI) 200 mg/I 600mg/I

pl-Irange 70-85 Notleasthan65orgreaterthan9 2

Magnesium+ sodiumsulphate

500 mg/I 1000 mg/I

Phenolicsubstances(asphenol)

0 001 mg/I 0 002 mg/I

References1. Postel, S., (1985) “Thirsty in a water-rich

world”. InternationalWildlife 15(6): 33-372. Beg, M.A.A , Mahmood, S.N. & Yousafzai,

A.H.K. (1975) “Industrial effluent, theirnatureand disposalm Karachi region: Part-i.Survey of the polluted Lyari River”. Proc.PaksitanAcd.Sci., 12: ii5-i31.

3. Beg. M.A., Mahmood, S.N; Naeem, S.N &Yousafzai, A H.K. (1984). “Land basedpollution mid the marine environment ofKarachi Coast”,J Sci md.. Res.27(4): 199-210

4 IUCN & Government of NWFP, EP&DDepartment(1994). “Kabul River Pollution”.

5 WHO (1976). “Pakistan’ Report of WaterSupply and Sewage Study”. Vol 1,WHO/Workd Bank Cooperative Program.Geneva

6. WHO (1984). “The InternationalWater Supplyand Sanitation Decade. Review of NationalBaselmeData” Geneva

7. WHO (1983). “World Health StatisticsAnnual1983”. Geneva.

8. Sattar,SyedA. Sattar (1987). “Drinking WaterandHumanHealth: An Expatriate’sAssessmentof the Situation in Pakistan”, ScienceTechnologyand Development,6(6): 48-54

9. Bag, M.A.A.; Bag, S.N Mahmoodand SitwatNaeem.(1989). Pak. J. Sd. md. Res.32(12),795

10. WHO. (1988) “International Standards fordrinking water”. Geneva.

Table6- Radioactiveconstituentsofdrinking-water

28

MEMBRANES AND OTHER PROCESSESTO IMPROVE THEQUALITY OF DRINKING WATER

Muhammad AshrafChaudhryPakistanInstitute of NuclearScienceandTechnology,P0. Box No.1356, Islamabad

ABSTRACT Recent developmentsin econoimcal and industrial fields, coupled with populationenhancedloadhasresultedinto further demandsfor the potableanddrinking watersupplies In the urbanand rural areasofPakistanthequality of drmkingwaterhasbeena point of discussionandattention sincelong Contributionsof the toxic metal ions and bacterianormally challengethe health of the peopleRecentlyavailabletechnology in the membranefield has provided reverseosmosisand electrodialysisprocessesfor waterdemineralizationand removal of the undesiredcomponentsfrom Water for publicconsumption In fact reverseosmosishas gained lead over electrodialysisbeing a simple, type offiltration process,working under mechamcalpressureand also having applicability to sea waterdesalination Therole of this andtheotherprocessesto removethe cations,anionsand bacteriahasbeen

discussed The benefitsof the reverseosmosisand other filtranon processeshave been describedforgeneralawarenessThe useofultraviolet light rays asa waterdisinfectanthasaisobeendiscussed

IntroductionThe healthof the peopleis of prime importance.

The drinking water suppliesin Pakistanhavebeensometimes deteriorated to harm the healthof theusers. Therefore water quality is to be ensured.Quality of water is challenged by (i) suspendedmaterials (ii) dissolved materials, which are bothorganic as well as inorganic in nature and (iii)bacteria,viruses,protozoa To get rid of thesethreetypes of species,spoilmg water quality, there aredifferent water purification methods~~These areclassicalas well as moderntechniques.The moderntechniques are based on membranes and otherchemical and physical processes The use of thegivenprocessesdependsupon the type of impuritiespresent.In this article the role of some of theseprocessesto purify water has beendescribed.Thisarticle will be limited to some of the toxic metalions with a brief reference to the bacteria andvirusespresentin water andhow to get rid of theseIt can be noticed that in Palustan 5.75 millionhectaresof land has undergroundwater with lessthan 1000PPM concentration and 1.84 millionhectareswith concentrationrangeof 1000-3000PPMand 4.29 million hectareswith concentration >3000 PPM°8~.As such 52% of C.C.A. has under

groundsalinewater, which stressestheneedfor thedesalting techniquesto be applied to use the fullpotential of watçr for drinking as well as agriculturepurpose.

Limiting Valuesof DissolvedIonsThe limiting amountsof various ions, which

affectthe quality of water are given in Table ~ Itmay be noted that though the limiting values fordifferent ions in different countriesare not the samebut should not exceedcertain maximumlevels e.g.the toxic elementslike, As, Ba, Cd, Cr, Fe, Mn,etc should not be allowed to be presentabove agivenconcentrationlevel, as shown in Table-i.

Different WaterTreatmentProcessesThere are different treatment techniques to

removeor reducethe level of dissolvedmetal ionsandbacteriafrom water,theseare:(1) precipitation;(ii) flocculationSedimentation;(iii) filtration;(iv) desalting by membrane process and

distillation; and(v) disinfectionusingU .V. radiation

The use of these systems to remove variousimpurities is providedbelow:

Table1: Limiting Valuesfor ~‘raceMetalsandother Ions inDrinking Water (Mg/M3)(4)

WHO E.C Switzerland France U.S.A. Germany

Alurniniuxn(AiJ - 50 500 - - 200

Arsenic(As) 50 50 - 50 50 40

Barium (Ba) - 100 - - i000 -

Lead(Pb) 100 50 50 50 50 40

Cadmium(Cd) 10 5 10 5 10 6

Chromium(Cr) - 50 20 50 50 50Iron (Fe) iOO/100(Y 300 iOO 100 50-300 200

Fluonne (F) 600/1700’ 700-1500 1500 1500 i400-2400 1500

Copper(Cu) 50/1500’ 50 1500 50 200-1000 -

Manganese(Mn) 50/500’ 50 50 50 iO-50 100

Nitrate (N03) 45 50 40 50/100 45 50-90

Mercury(Hg) 1 1 3 1 2 4Selenium(Se) 10 iO - 10 10 8

Silver (Ag) - 10 200 - 50 100

Zinc (Zn) 5000/15000’ 100/2000 1500 - 5000 100/2000

*Hjghest requiredvalue/Maximumpermissiblevalue:

29

Precipitation Flocculation and Filtration toRemoveToxic Metal Ions

RemovalofFeandMnPrecipitationis an old method Removalof Fe

and Mn by this processis discussedhere. In wellwater Fe andMn occurs as Fe~& Mn~and areto be removedfor technical and hygiemc reasons.These ions are oxidised by ozone, KMnO4 oroxygen to Fe(1I1) and Mn(IV) , which precipitateand are removed after filtration Conversion ofFe(II) to Fe(III) i’s ~‘fastand that of Mn(II) to Mn(IV)is slow but Mn(OFI)4 worksas a catalystto enhancethe reaction(

4> Oxidation is normally done bysaturationof waterwith atmosphericoxygen

RemovalofotherElementsAmong the conditionof the removalof the toxic

elements, like As, Ba, Cd, Cr (III & IV), Pb, Hg,Se, Ni, Cu and Zn, the parameterslike pH of thefeed water, valencey of metallic ions, amount offlocculate and the type of flocculant added, theinitial concentrationof the ions present, and theturbidity are to be determined and the feedconditions are to be fixed. The metallic ionsconcentrationlimits are shown in Table-2.

Table2: Limits ofMetallic Ions ConcentrationinWater~6~

Mm. g/m3 Max.0.10 040

100 800

0.10 0 400.10 0400.05 0.20

0.01 0 050.01 0 041.00 4 08

These elements behave differently and theirremovaldependson pH. usmga pH of 6.5-7, and aflocculant admixture of 5g/m3 Fe(III), As(IV),Cr(III), Pb(II) is removedafter precipitationup to> 90% or more under these conditions, Ba andCr(VI) are precipitatedandremovedto only a verysmall extent.

If we use a pH of 7.5 - 8, with all otherconditionskeeping the same, Ag, ~Cdand Hg arebetter precipitated Se(VI) precipitates poorly.Cr(VI) can be removedafter reducingit with Fe~2andprecipitatmgat pH 8-8 5. Upto 95% of Cr(VI)canbe removedm this way.

At pH 10 - 10.5, by meansof decarbomzation,flocculation, and scdementationby an admixture of~g/m3of Fe(I1I), good separationof a number of~netalions along with Ba is possiblebut Cr(VI) andSe(IV) arenot removed~6~

Theseare just a few examplesto indicate thatwiule treatingthe water a very careful consideration

is to be givento the parametersdescribedabove, toget a good quality supplyof water

ActivatedAluminaand CarbonFilters

(i) AluminaAlumina is a porous form of Al

203 with 150-400m

2 specific areaper gm of A1203 and density

app 3.3gIcm3,used for the removal of As, Se and

fluoride ions. It may be in different gramsizes.Forusually presentFe, Se and As concentrationlevels,at a pH of 5-5 5, alumma column can treat about1000 time volume of water comparedto its ownvolume, before regenerationwith 0.5-1% NaOHThe specific loadability is 50-70mg/din3, for Se and10-lSmg/dm3for As(IV) and needsmore conc ofNaOH to regenerate the column. The systeminvolves prior flocculation, sedimentation,settling,sandfiltration and then adsorptionby alumina.

Activated carbon filters removeboth organic aswell as inorgamc Hg A contact time of 6-12minutes removes upto 200mg/dm3 of Hgorganometalliccompoundsof Hg.

(ii) ActivatedCarbonAbsorbs low mol.wt. organics, chlorine, odour

producingnutrients from water, works well on 60-300 mol wt. materials. Does not remove salts butabsorbssomemetal ions. If not replacedafter givenintervals of time, producelargecoloniesof bacteriaand largeamountsof pyrogemcmaterials.

MembraneProcessesThere are a number of water treatmentsystems

basedon membranes.Theseare basedon filtrationor appear to be based on simple prmciple offiltration. Theseare briefly describedbelow.

There are different engineeringconfigurationsWof these processes modules e.g. spiral wound,hollow fibre or tubular modules, which are notdescribedherein detail for the sakeof brevity.

(i) Microfi itrationRemovesfrom 100!.im to 0.10~imsize species

from water e.g. pollen (100~im),starch (10l.Lm),bloodcells (li.tm), bacteria(1!.tm to 0.1~im)

(ii) UltrafiltrationRemovesspeciesfrom 0.0ll.tm to 0.OOlj.tm size

e.g. DNA, viruses (O.Olj.im), albumin (0 01l.tm),glucose(0.001~im).

(iii) ReverseOsmosis(R.0) orHyperfiltrationRemovesall the abovesized speciesalong with

dissolved solutes e.g. NaCl, Kcl. These all usemembranes, which reject given species underdifferent levels of mechamcallyapplied pressures,by p~impmg.The membi~anelife is 1-3 years.Removesall organicsof mol.wt’� 200. Removes>95% salts from brackishwater. Two stagesremove99.9% salts. All bacteria,viruses andpyrogensareremoved Membranesare affected by the pH and

I,

30

chemicalconditions It has beenappliedto both seaand brackish waters. It is cheaper, less capitalintensive, simple and easily applicable to homewater purification Systemswhich use low pressurescan be produced. For that purpose membranes,which have large fluxes, are to be used; which canbe produced and applied in Pakistan It is nowindustrially preferred processto distillation in allrespects. Consumesless energy. The users andsuppliers need to be educated for the type ofmembranes and R.O systems to suit theirrequirements.

(iv) ElectrodialysisThis processis basedon cation (CEM) and anion

(AEM) exchangemembranes,which are arrangedinthe form of a numberof membranepairs.Water isrun betweenCEM and AEM, under the appliedcurrent and voltage.The ions are pulled out of theflowing liquid through the membrane, therebyreducingthe concentrationfrom there(calleddiluatestream)andconcentratmgthe otherstreamknown as(concentratestream)

At a time hundredsof membranepairsare fixedSo the energy consumed is economised Thisprocess is applicable to water upto 3000ppmconcentration and normally used to reduce theconcentrationupto 500-800ppm After that theresistanceof the systemmcreasesto enhancetheoverall energy required. This system works at apumpingpressureof nearly60 psi

(v) Distillation and Non-membraneProcessesIt is the change of the phaseprocessand has

been used extensively in the past In the presentform, it existsas multistageflash distillation (Fig 3)and multi-effect boiling, recovermgheat from thevapours, transferrmg to the incommg cold feedstreams to increase the overall efficiency of theplant to distill water As such there are plants,whichcanconvert12-16 k gms of water per Kg ofsteam.All the morgamcimpurities, mcluding toxicmetals ions canbe removedto recoverpure water,which normally evaporate at temperaturehigherthan that of water. Hence for producing drinkingwater quality, the distillate is mixed with highersalinity water This consumesmore energy, whenusedfor desalinationof water. Many million gallonsper day capacity plants are working in differentparts of the world, including Middle East, Russiaand Japan. It involves higher capital as well asrtinnmg costs to get distilled water The tripledistilled watersareusedto get rid of pyrogensto beusedm dialysisof blood.

Vapour compressionbaseddistillation systemsare there as well. This is not competitive withmembrane processes.Freezmg is another phasechangeprocess,which is basedon the principle offreezing the saline water, whenthe crystals formedare free of salts and after washing and melting

provide pure water The latent heat of waterfreezing, being less than that of the latent heat ofwater vaporisation seems to have involved lessenergy,but this processefficiency is outsetdue tothe difficulty in pumpingor transportingsolid watercrystals.

(vi) Ion-exchangeProcessIon exchangeresins are used for deionisation

The anion exchange resins (AER) can removeanions and cations exchange resins (CER), thecations.CER are regeneratedto (H~)and AER to(-OH) forms As suchCa~,~ Na~andK~getexchangedwith W and Cl, S042, F, NO-3, with -

OH The purified water as suchwill haveH~and -

OH which combine to form H2O. But the level ofH~and 0H presentin purified water may be indifferent amounts The ions are absorbed in thefollowing order first

Cattons:Ca~2> Mg~2> K~ > Na~ > H~

Anions NO-3 > S042 > NO~ > Cl- >

HCO3 > OH = FThis is why to remove Ca

12 and Mg~2fromwater the resinsare regeneratedby Na~or H~

Deiomsers do not remove orgamcs, virus orbacteria,but rathersometimes give way to bacterialcolonies if not replaced for a longer periods.Normally used for removing Ca~~and Mg~4ionsfrom feed supplies, if presentabovea given level

U.V. DisinfectionThe U V. radiations are producedby passing

current throughlow pressureHg vapours containedin an evacuatedtube The U.V range for killingmicrobesis 200-300nm.The radiationskill viruses,algae, bacteria, protozoaand fungi. 254nm wavelength radiations are close to the most effectivekilling wavelength of 260nm being maximumlyadsorbed E-coli require7x103 microwatt/scm2 andprotozoa 10 5xl04 mw/seccm2. U.V energy dose= Intensity x contact time in secondsU V.transmissionat >75% is required at 254nmwavelengthradiation So water to be treatedshouldbe freeof suspendedconstituents

Humic acid, tanninsand Fe are found in waterandabsorbU V radiationto reduceits dismfectmgaction Ca and Mg ions if precipitated may alsoreduceeffectivenessof this process.So precipitateand filter the suspendedprecipitates from waterbeforeapplying U V. radiation

The U V tube is recomm~ndedto be sleeved,other wise its relative efficiencywill decreasewithtemperature5-1000 gallon per minute purifier areavailable.The systemlife claimed is 6000 to 12000hrs. Required dose for dismfectrion is 38000mw/s cm2 for contaminated waters and 1600mw/s cm2 for normally supplied water~7~Asdifferent dosesare to be given to kill different typeof harmful bacteria, so the product samples are

31

neededto the testedto fix the U V.dose and ensurequalityof water.

ChemicalDisinfectionThere are different types of bacteria, enteric

virusesand protozoa,which are dangerousto existin water, as they cause the diseaseslike, typhoidfever, cholera,gastro-enteritis,heartenamohesandso many other diseases.Disinfection of these maybe performedby dosingthe drinking water streamswith chlorine, 03, and C120, as higher the oxidationpotential higher is the disinfection. The order ofdisinfection power by various reagents is givenbelow

03 > Cl20 > Cl2 > Br2 > 12They kill bacteria, reduce the slime growth on

filters and in sedimentationbasis.03 andCl2 also reducefilter water turbidityThere are some ill effects of disinfection also

e.g.(i) Cl2 reactswith humic acid and low molecular

weight organic compounds to form toxicchlorinatedorganics

(ii) 03 formsaldehydeswhich aretoxic in nature.(iii) Cl20 forms chlorate and chlorite, which are

also toxic in nature.Thereforea calculatedamountof oxidisersare to

be usedto avoid theaboveill effects

Reconunendations(i) To improve the water quality, different typesof

techniquesshouldbe used,keepingm view thetype of constituentspresent.Only filtration isnot the only solution as indicated in thepreviouspages Thereforeall the systemsmustbe considered.

(ii) Reverseosmosisunits are recommendedto beproduced locally For that collaboration withfirms, supplying such equipment in Pakistan,may be asked to provide technology ofmembranesandmodulemaking/manufacturingin Pakistan. Initial investments may lead tolargesavingsif Govt. supports I) researchanddevelopmentactivity of membraneprocesses.ii) encouragethe investorsand provides funds

to have R 0. membranemodule industry inPakistan

(iii) Small units working on low pressuresandbrackishwatersare easyto make. This activitymay be started locally. Traditional waterpurification technologyis alreadythere

(iv) A combination of Ion-exchange RO andFiltration + distillation and other suchcombinations must be looked into beforedesigninga water purificationplant

(v) R.O-cum-tubewellsystemsto convertbrackishwater to potablewater may be used to recoverpartof salinewaterpumpedand energy.

(vi) The Baluchistancoastalareas,and many partsof Punjab, Sind and NWFP haveundergroundbrackish water, which can be purified usingmembranetechniques.It is recommendedthatproperattentionbe ginen to this.

AcknowledgementThe author likes to acknowledgethe support of

Dr. M. Zafarullah to provide the facilities tocomplete this work and Mr. A. Hafeez to type thismanuscript.

References1 Sourirajan (1976) “Reverse Osmosis and

Symmetic Membranes”, National ResearchCouncil, Canda

2 Ashraf Chaudry (1980). The Nuclear, 17(1).37-45

3 Ashraf Chaudry (1982). “Minimum EnergyConsumingWater ConversionProcess” Proc.First National Symposium on EnergyConservation,Feb. 1980, Islamabad,Pakistan.

4. Ginocchio. (1982). Sulzer Technical Review.65(1) 23-26

5 Ginocchio, J. Tylmann (1980). SuizerTechnicalReview.63(1): 34

6 Ginocchio et al 91980). ChemischeRundschau,Zurich, No.29

7. Carriganet a! (1992). Engineering Horizons.73(5) 3-7

8 The World Bank (1967) “Study of WaterandPowerResourcesof WestPakistan”.

32

SEPARATION AND SPECIATION OF ORGANO-PHOSPHORUSPESTICIDESBASED ON HYDROLYSIS USiNG REVERSE PHASE HPLC

JasmmShah, M. RasulJanandKahkeshan SaeedDepartmentof Chemistry,University of Peshawar

ABSTRACT~A new method for separationand speclatlon of organophosphoruspesticideshas beeninvestigatedusing reversephaseHPLC Pesticidesare hydrolyzed by the addition of sodiumethoxide,

the organiclayer is separatedfrom the aqueousphasewhich containthe acidic hydrolyzedportion of therespectivepesticidesDifferent pesticidesgive different acidic productson hydrolysis leading to varianon

in the retention time The hydrolyzed productsare injected and separatedon reversephase HPLCIdentificationand quantificationis done by runningtherespectivestandards

IntroductionOrganophosphoruspesticidesvary in toxicity and

half lives Due to their excessiveuse in recentyearstheir determinationin water bodieshasbecomeveryimportant This necessitatedthe determination oftotal pesticides on one hand and identification ofspecific organophosphoruspesticideson the other.Organophosphoruspesticidescanbe determinedas awhole group by HPLC, gas chromatographicandthin layerchromatographicmethods~8~Alternatelyphosphoruscan be determinedafter decompositionor hydrolysis by Spectrophotometricmethodst9~i3)

Moreover the non-phosphorusgroup afterhydrolysiscan also be determinedspectrophotometricallyby areaction dependingon some propertiesof the non-phosphorus group~4’7>.Non-phosphorusmethodscan oftçn be madespecific for a smglepesticide,oratleast for a group of related pesticides Suchspecific methodsare of advantageif one of severalpesticidesm a sample needsto be determined. Inthis paper a new HPLC method capable ofspeciationand determmationof organophosphoruspesticides basedon hydrolysis is presented.Thiscould be usedfor a quality checkand certificationofthe drmking water sources with respect tocontaminationoriginating from an excessiveuse ofthe fertilizers.

Experimental

InstrumentHPLC systemconsistedof a BacharachColeman

Tn Det with a pecosphere3x3 C18 cartridgecolumn, Perkm Elmer 100 seriespump, recorderand thermostatedwater bath were used during thisinvestigation.

Reagentsp-mtrophenol, fumaric acid, carbontetra-

chloride, sodium metal, ethanol and methanol ofA R. grade and commercially available pesticideswereusedwithout further purification.Solutions(1) p-mtrophenol(1000ppm) solutionS

Stock solution of p-mtrophenol waspreparedby dissolving0 1 g of the reagentin distilled water and dilutmg upto 100 mlin a volumetric flask.

(2) Fumaricacid(1000 ppm) solutionSStock solution of fumaric acid waspreparedby dissolving 0.1 g of fumaricacid in distilled water and diluted upto 100ml in a volumetric flask.

(3) Sodiumethoxide(1%)solution:

1% solution of sodium ethoxide waspreparedby dissolving 1 g of sodiummetalin ethanoland dilutedupto 100 ml

(4) Mobile Phase.

Water Methanol mobile phase wasprepared in 1:1 ratio and degassedbybubbling N

2 gas through the solution forabout10 minutes

ProcedurePesticide sample (0 1 ml) was taken in three

separateseparatoryfunnels, 6 nil of 1 % sodiumethoxide, 5 ml of water and 5 ml of carbontetrachloridewere then addedto eachseparatoiyfunnel.The resulting solutions were mixed well using ashakerfor two minutesand transferredto respectivebeakers. The resulting solutions m beakers wereheatedon water bath for 15 minutesat 60°C.Theaqueousphase was separatedfrom organic phaseusing separating funnel The organic phase wasretainedfor analysisby HPLC using reversephasechromatography.

ResultsandDiscussionsSeparation of pesticides is one of the key

requirements for assessing the toxicity of aparticular pesticide in the environment. Totalorganophosphoruspesticidescan be determinedbymolybdenumblue method while sulphur containingpesticidescould be determinedby methylenebluemethod In the presentwork HPLC method wasexploited for the speclation and determinationoforganophosphoruspesticides The generalstructureof the organophosphate pesticides may berepresentedas

WhereR1 andR2 are methyl or ethyl groupsandX is an orgamc radical. The R1 and R2 substituentgroups are less easily hydrolyzed from thephosphorusthan is the X group. In the hydrolysismethodsthe pesticide is hydrolyzed with alkali to

33

break the P-O(S)-X link, and then the liberatedorganicsubstituentis isolatedand determined.

On hydrolysis methyl parathiongive rise to thefollowing products0, 0-dimethylthiophosphateandp-nitrophenol

Similarly malathion was hydrolyzed into 0, 0-dimethydithiophosphate and fumarate as givenbelow

Conditions were optimized for the separationand identification of p-nitrophenoland fumaric acidusing reversephaseHPLC with UV detector(254nm) on a pecosphereCl8 cartridgecolunm Water:Methanol (1 1) was chosenas the optimum mobilephase with a flow rate of 1 0 mi/mm. Theidentification of the componentswas madeboth byfollowing the retentiontime andthe spiking methoddata. As different pesticides leads to differenthydrolyzed products leading to variation and thisproperty was exploited for speciationin mixture.The retention time of fumaric acid and p-nitrophenol was found to be 0 2 and 0 6 minutesrespectively Workingstandardsof fumaricacid andp-nitrophenol were injected in the range of 10-50ppm, whereinthe detectionlimits for p-nitrophenoland fumaric acid werefound to be 3 0 ppm for bothwith 10111 injection volume The organicphaseofthe hydrolyzed product of methyl parathion andmalathionweresimilarly injected(10111) The activeingredients in the commercial products of thesepesticideswere calculatedfrom the peakheight oftheir organic hydrolyzed products using therespectivecalibration plots.The results are given inTable-l As can be seen from this table that theconcentrationof pesticides in these commerciallyavailablepesticidesare lower than the label value

Table 1 DeterminationofActiveIngredientsInPesticidesUsin ReversePhaseHPLC

Pesticide Active Ingredient(g / ml)

Found LabelValue

Methyl ParathionMalathion

0 156 0 50 196 0 5

ConclusionDifferent pesticides lead to different products

after hydrolysis Pesticidescould be identified as

well as quantified basedOn the retentiontime andpeakheight data of the hydrolyzedproducts of thespecific pesticide Speciationstudies for malathionand methylparathionwereconductedexploiting thistechniqueusing reversephaseHPLC with water-methanol as mobile phaseand UV detection. Afteroptimization of mobile phaseand the retentiontimethese pesticides were determined in differentpesticideformulations The methodis fairly simple,economicaland comparewell in term of detectionlimit (30 ng) with the other standardestablishedgaschromatographicmethods

References1 Blanchet, P F (1979) J. Chromatog 179 1232 H Egan, E.W.Hammond and J.Thomson

(1964) Analyst 89 1753 Dawson, J A, Donegan, L & Thain, E M

(1964) Analyst 89 4954. Watts, R R (1965) J.Assoc.of Agnc Chem.

48 11615. Patil, V.B, Padahkar, S V & Kawale, G.B

(1987) Analyst, l12~17656 Bunyan, P J (1964) Analyst,89 6157. Kiso, Y Li, H, Shigetoh,K, Kitao, T& Jinno,

K (1996) J Chromatog 10 2598 Ding, H.W & Amirav, A (1997).Anal. Chem.

69 14269 Norris, M.V Vail, W A & Averell, P R.

(1954) JAgric. FoodChem.2 57010 Clark, E R. & Qazi, I A (1980) Analyst. 105

56411 Seshaiah, K & Mowli, P (1987). Analyst.

112 11812 Naidu, U V , Gangaiah, 1, Ramadevi, P,

Seshaiah,K & Naidu, G R K. (1990) Talanta.37 761

13 Rasul Jan, M; JasminShah& RubnaMasoud(1991) J Chem Soc Pak. 13~263

14. Santi, R & Bazzi, B (1957) Chem. Abstr.4632

15 Wollenburg, 0 & Schrader,G (1956). AngewChem 6841

16 Averell, P R. & Norris, M V. (1948) Anal.Chem 20 753

17. Hall, S.A , Stohlman,J W. & Schechter,M S.(1951) Anal Chem. 23:1866

w

34

DRINKING WATER QUALITY MONITORING IN THERURAL AREAS OF RAWALPINDI

M. Aslam Tahir, Bashir A. Chandio, M. Abdullah & A. RashidPakistanCouncil of Researchin WaterResources

ABSTRACT. A casestudy to investigaie the statusof drinking waler quality was conductedin the ruralareasof Rawalpindi district coveringGujar Khan Kahuta, Murree. Rawalpindi and Taxila Tehsil For

this purpose,water sampleswerecollectedand analyzedfor about24 waterqualiiy parametersincludingphysico-chemical.inorganic constituents,trace elementsand bacterial indicators Drinking water qualityprofile of the survey areawhere the parameterexceedsthe WHO guidelines are preparedand healtheffects are also highlighted Most of water samplesare not found fit for drinking purposes due to

presenceof colitorm and E coli, Nitrate, Iron and Sodiumare found in high concentrationin sonicwater samples This study demandsthe due attention of our policy makersand agenciesresponsibleof

drinking waterschemesfor the provisionof safedrinking waterespeciallyin the rural areas

IntroductionThe rapidly increasing pressureon available

water resources from agricultural as well asdomestic section, less attention is being paid towater quality As a result, water quality isdeterioratingday by day and its consequentimpactsare becomingpermanentin shapeand deterioratinghuman healthin domesticsector and stagnantevendegradationof agriculturalyields This water is thekey to future of life sustainability and economicdevelopment

Most of the communicablediseasesare waterborne and those diseases cause morbidity andmortality. In Pakistan,despiteof the high mortalityrate specially in the infants due to unsafedrinkingwater, no attention is being given to the drinkingwater quality improvements.Neither the public northe decisionmakerare well awareof the gravity ofthe drinking water situation However, in someplacessomeremedialmeasuressuchas filtration andchlorinationhavebeentakenbut theseare quite in-sufficient and in efficient and confinedonly in majorurbanareascovering32% populationof thecountryThe remaining 68% of the rural population isdrinking water of poor quality. Awarenessamongthe massesabout the safe drinking water is to bepropagated The poverty, low education rate,political instability, socio-culturalproblemsand lowpriority to enhancesafe water supply coveragetomassesare major factors.

The water supply systemsin most of the cities,towns and villages carries numerous injuriousbacteria and other pollutants. Some of thecontaminationare due to the geological~trucmreofthe areabearing un-healthy minerals affecting thetasteandcharacteristicsof water. Someexamplesofthesemineralsare chloride, lime, magnesium,lead,chromium and zinc etc The composition of watervaries widely in its main inorganic constituentswhich are sodium,potassium,calciumbarium, iron,zinc, bicarbonate,chloride, sulphate,phosphateandnitrate. Orgamc compounds like pesticides,detergents,lindane 2, 4-D, phenolic substancesandcarboxylic acidscanalso causewaterpollution.

The news in respectof water borne diseaseswere become common feature in the daily news

papers circulated in twin cities of Rawalpindi andIslamabad It has been reported in the EnglishNewspapersthat about200 childrenas well as 40 to50 adult patients suffering of water borne diseasesbeing admitted daily to Rawalpindi hospitals, Thepatients suffering from such diseases mostlybelongedto surroundingrural areasof Rawalpindi.Diseases like jaundice, gastro-enteritis (stomachdiseases),diarrheaand typhoid areon the rise duetothe consumptionof unhygiemc water and mixing ofpotable water with the seweragewater Some ofthose patients were brought to hospitals in seriousconditionand admitted to intensivecareunits (ICU)Children easily fell victim to such diseases,theygenerally used contaminatedwater and sufferedfrom lack of propercare To arrestthe severityandto kiiow the causesof problem, the drinking waterquality monitoring study has been conducted ofRawalpindi rural areas covering five Tehsil i.eGujar Khan, Kahuta, Murree, Rawalpindi andTaxila This researchstudy was confinedto assessthe existing water quality status and to suggestremedialmeasuresfor the improvementof drinkingwaterquality on the basisof researchfindings.

MethodologyTotal numberof 29, 19, 23, 19 and 26 water

sampleswere collected randomly from Tehsil ofGujar Khan, Kahuta, Murree, Rawalpindi andTaxila respectively About 24 water qualityparametersweredeterminedto identify thepollutionproblems i e. harness, alkalinity, aluminium,sodium, calcium,, chloride, nitrate, conductivity,colour, copper,. free carbondioxide, magnesium,pH, phosphate, potassium, taste, total dissolvedsolids, iron, zinc and manganesecontents,E. cob,coliform and non coliform and the water qualityparameters compared with WHO standards todifferentiate the polluted and non polluted watersamples the coliform bacteriaare detectedby theirability to ferment lactosein cultureat 35°Cor 37°CThe collectedsampleswerebrought to the PCRWR,laboratory within the shortest possible time forreliable analysis. Some preliminary physico-chemicalobservationswere recordedat siteby using

35

field equipment and water pollution kit Standardanalytical proceduresand methodswereadopted

ResultsandDiscussionsThe topographical characteristics and water

sourcesof the study area from where the watersampleswere collected are given at Table I Thepeopleof the study areausually fulfill their domesticand drinking water requirementsby collecting waterfrom nearby wells, tubule wells, ponds, watersupply schemes,hand pumps, springs etc. It wasobservedduring the water sampling that the closeand covered water supplying systems weredischargingmore clean and transparentwater thanhe openair systems

The Table 2 is depicting the mean values ofwater quality parameters determined and thenoverall assessmentof the water quality found in thestudy area is drawn wherever the extremeconcentration/ level of any parameterwas observedthe samehasbeenelaboratedin the text

In some areasituationof water quality was veryinferior, alarming and unbelievable The twoexamplesare given to show the picture regardinghygienic supply of water to the rural population.

Thevillage Dukhi Dukhli Begumin Tehsil GujarKhan where uncoveredponds are being used as asource of drinking water for human and livestockThe water contains growth of coliform, noncoliform and E cob.

The village Gorakhpur (Udiala) in TehsilRawalpindihashighernitrate contentsi e. 63 3mg/Ithan the permissible limits of WHO (lOmg/l)Excessnitrate in water is harmful for humanhealthespecially to the kids; causes blue baby disease,infantile methemoglobinemiaand death ChangesofNitrate (NO3) into Nitrite (NO7) in human mouthorgut and forms-N- Nitosamine,a suspectcarcinogen

The date comparedwith WHO standardsand anumber of pollutions were identified.Waterqualityparametershaving desirablevalues are collectivelydiscussed

Desirable Water Quality ParametersAbout 24 water quality parameters were

analyzedto identify the pollution problems Watersamples were found to be fit with respect toalkalinity, aluminum, calcium, chloride,conductivity, colour, copper, free carbondioxide,magnesium,pH, phosphate,potassium,taste, totaldissolvedsolids and zinc contents.The values ofiron were found within the desirable level in thewater samplesof Gujar Khan, Kahuta, Rawalpindiand Taxila In samplesof Rawalpindi and Murreethe quantityof manganesewaspresentin most casesunder the desirable limits The water samplescollected from Murree and Rawalpindi Tehsil werefound safe in respectof nitrate WHO has given 250mg/I and 200 mg/l a highest desirable levels forchloride contents and sodium respectively As perthe limits, only 2 samples in respect of chloride

contents and 7 sampleshaving sodium more thanWHO standardshowever,water samplesof otherTehsil were within the limits in respect of chloridecontentsand sodium.

Undesirable Water Quality ParametersThe drinking water quality parameterswere

found above the highest desirable level of WHOstandardsare hardness,nitrate (N), chloride, ironand sodium, Most of the testedwater sampleshavenormal concentrationsof chloride, iron and sodiumin Kahuta, RawalpindiandTaxila. However, 10.3%and 20 7% sampleshavemorechloride and sodiumrespectively in Gujar Khan, and Murree, 34 8%sampleshave more iron than that water qualitystandardsThe meanvaluesand rangesareshown inTable3 The resultsare discussedbelow.

(i) HardnessAlthough the meanvaluesof hardnessin water

samples of Gujar Khan, Kahuta, Murree,Rawalpindi and Taxila are found less than theWHO highestdesirablelevel (500 mg/I of hardnessas CaCO3) 352 8, 440.8,3358, 320 and406.7 mg/lrespectively,neverthelessabout 14% 26% 4% 10%and 11 % water samplescollectedfrom Gujar Khan(125 to 825 mg/l), Kahuta (250 to 762 mg/l),Murree (74 to 537 mg/I), Rawalpindi (58 to 687mg/I and Taxila (262 to 525 mg/I) were possessinghighvalues than WHO standardsThe literaturehasindicated the reasonsof high CaCO3 in water whichare i) Calcium and magnesium in the form ofminerals and lime stones + chalk (CaCO3) arepresentin soils and ultimately in water, ii) Industrialproducts as well as polyvalent ions of zinc,manganese,aluminum, strontium,barium, iron areresponsiblefor hardness

The presenceof high contentsof CaCO3in waterleads to an increasedincidence of urolithiasis andpossesslaxative properties due to associationofmagnesiumwith the sulphate ions. A number ofstudies have demonstrated significant negativeassociation between water hardness andcardiovasculardiseases.Other diseaseslike certainnervous system defects, anencephaly, prenatalmortality and various types of cancerare correlatedwith hardnessof water The hard water has beenreported the main causes of house hold pipeschoking with deposited scale, encrustation onkitchenutensilsand increasingsoapconsumption Ahardnesslevel of about 100 mg as CaCO3 per literprovides an acceptablebalance betweencorrosionandencrustation.

(ii) Nitrate (N)The mean concentrationsof nitrate nitrogen

(mg/i) in water sampleswas found more than WHOstandards(10 mg/l) in study areaviz Gujar Khan(11 4), Kahuta(17.7), Rawalpindi (17 5) andTaxila(8 67). A reasonable%age of watersamplesare notfit for drinking purpose in Gujar Khan (24%),

I.

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36

Table 1 To’7ographicalcharacteristicsand water sourcesof the studyareaS.No Tehsi] Source Topography1 GujarKhan Well, Tubewell, hand Pump,WaterSupply, Pond Plain & SemiHilly

2 Murree Spring, Well, WaterSupply Hilly area

3 Kahuta Well, Hand Pump,WaterSupply. Spring Hilly area

4 Taxila Well, Tubewell, Spring Plain & Semi Hilly

5 Rawalpindi Well, Tube well, Hand Pump,WaterSupply -do-

Table2. Intensifyofpollutionfoundin watersamplescol lectedfrom the studyareaWater Quality WHO GujarKhan Kahuta Murree Rawalpindi Taxila

Parameiers Standards

mg/I

* * *** ** * ** ** * **

Hardness 500 4 138 5 263 1 43 2 105 3 ii 5Nitrate(N) 10 7 24 1 5 26 3 - - - 3 ii 5

Chloride 250 3 10 3 - - - - - - - -

iron 03 - - - - 8 348 - - - -

Sodium 200 5 17 2 - - 2 10 5 - -

ECob - 19 65 5 16 84 2 17 73 9 13 68 4 14 53 8

Coliform - 25 86 2 15 78 9 20 87 17 89 5 20 76 9

Non-Coli - 25 86 2 17 89 5 20 87 17 89 5 19 73 1

Total No of samples 29 19 23 19 26

* Numberof pollutedsamples, ** Percentageof polluted samples

Table3 The ConcentrationofNO3 (N), Cl, Na & Fe in watersamplesofstudyareaMain StudySite/Range

SamplingSites WaterSource Conc (mg/I) Parameter

Gujar Khan(0 3-72 2)

Mera ShanisMohra BhatianGalyanaChakDolat

WellWellWellWell

12 7i3 042 548 6

NO3 (N)-do--do--do-

Gohra Well 72 2 -do-RanjaliPhadana

T WellWell

107269

-do-Ci

SyedAddaManghotGalyanaSyedAddaManghotJajjahGorha

WellWellWellWellWellWellWell

1540513360

1520420246354

-do-

-do-Na-do--do--do--do-

Kahuta(02-111)

Police StationKalar SydanPhakrhal

W SupplyWellWell

10825 452 1

NO3 (N)-do--do-

Chani Bazar Well iii -do-FG Boys SchooiDalla Well 13 3 -do-

Rawalpindi(0 25-92 1)

MaraMohraMudhal

JinnahTown Adyala G SchoolGorakhpurNew LalaZarMaraMohra

WellWellWellWellWell

26

1392 163 661 2

NO3 (N)

-do--do--do--do-

Dhok Badhal Well 202 -do-Well 230 -do-

Taxila(0 1-17 8)

UmrialThatta Khalil

PindNowshehriKhanChowkar

WellWell

WellWell

11 271 86119 5

NO3(N)-do--do--do-

Murree Romal VillageGhekaGaliAliotPatriataAbbasiHotal L TopaGhurial GhekaGab

BanseraDaliGorhaGali

SpringSpringSpringSpringSpringSpring

SpringSpring

0 370 360 320 320 390 370 35

0 36

Fe-do--do--do--do--do--do-

-do-

37

Kahuta (26%) and Rawalpindi (11%) due to highconcentrationsof nitrate nitrogen (Table-3). Thechemical fertilizers, decay of vegetableand animalmatter, domesticeffluents,sewagesludge, industrialdischarges, leachates from refuse dumps andatmospheric washout are considered the maincontributorsof nitrate (N) in water sources Higherlevels of nitrate are found in ground water ascomparedto surfacewater. High levels of nitrate(N) are responsible for cause of infantilemethemoglobtnemia(30-40% lead to anoxia) andultimate death Infants may suffer from gastrointestinal disturbancesThe pregnantwomen are atgreaterrisk than the generaladult population.

(iii) SodiumThe NaCl salt is found in rocks (rocksal),

silicate minerals, amphiboles and feldspars, seawater and it is presentabout 26 g/kg of the earth’scrust. Sodium saltsare addedin water systemfromthe washing of salt affected soils, domestic andsewerageusedwater and industriesof glass, soap,leather,pharmaceutical,chemical,treatmentplants,ice and ice creammaking, food industry Excessiveintake of sodium chloride causes vomiting,convulsions, muscular twisting, rigidity, cerebraland pulmonary oedema, deterioration of chroniccongestive heart failure, hypeertension and illeffectshavealso beendocumented.Freshfruits andvegetablecontain from 10 mg to 1 g/kg of NaCI.Milk containsa relatively high proportionof sodiumchloride i e 1 5 g/kg The minimum NaC1requirement is about 120 mg/day WHO hasrecommended200 mg/l as a guidelinevalue

(iv) ChlorideIt is distributed in the form of NaCI, KC1,

CaC1,, salts in the soil and Waterbodies, Effluentsof chemical industries, oil well operation, sewagedischarge,irrigation drainage,refuse leachatesandseaWater intrusion in coastalareasare the majorfactors of chloride addition in water The Chlorideis essentialas about530 mg of NaCI salts per dayare excreted from the adult human body It isestimatedthat more than 9 mg of Cl per kg of bodyweight is needed. The taste threshold levels forNaCl, KCI, CaCI, in water are 210, 310,222mg/l.Approx. 600 mg. of chloride per day are ingestedina salt free diet. An average intake from drinkingwater is approx 100 mg/day.

(v) IronThe Iron in water is presentin the ferric (Fe~3)

state.It is addedin water from rocks, minerals,acidmine drainage, iron related industries The Fe isessentialin humannutrition for body infrastructures(bones)and nervoussystemanddaily requirementis7-14 mg. The higher intake resultshemochromatosis Ferrous salts are unstable andprecipitate as insoluble ferric hydro-oxide, which

settlesout as a rust colouredlayer, suchwater oftentaste unpalatable, stains laundry and plumberingfixtures WHO has recommended0 3 mg/l as aguidelinevalue

Study Area ____________ ______________

GujarKhanKahutaMurreeRawalpindiTaxila

This study indicates clearly that the drinkingWater being suppliedby water supply schemesandusedby rural populationof RaWalpindi district areais not safe for drinkingpurpose

Measuresfor SafeDrinking WaterA numberof measureshavebeenproposedfor

provision of safe and pure drinking water topopulation~f rural areas i) The contaminationofwater drawn from wells, ponds hand and otherpumps etc., is very common due to presenceofnearby septic tanks and pit latrines in the ruralareas The problem needsto be studiedin detail toarrive at appropriatedesignsof the whole systeminorder to get contamination free drinking waterii) The biologicalcontaminationcanbe controlledbysimple chlorination. The water suppliedby regularschemesmust be chlorinatedbefore its dischargeinto the mam supplysystem Chlorine may be addedto drinking water supplies to destroy harmfulbacteria Potassium permanganateand bleachingpowdermay also be usedfor the sterilizing of wellor pond Waters All domesticundergroundandoverheadtanks should be cleanedperiodically iii) Thenew Water supply schemesmay be approvedandimplemented only after investigation of Waterquality. The Govt. must initiate safe“Water supply,schemes in rural areas where chemicatcontamination’sare in excesslike iron, manganese,Nitrate, etc the alternatesourcesof water may besearchedout by usingResistivity survey techniques.iv) In-house water filters such as Ceramic WaterFilter using silver coated sand may be used forwater decontammationandremovalof dust, silt etcv) To set up guideline values continuousresearchand monitoring National Water quality standardsstrictly by enforced vi) Low cost water treatmenttechnologiesbe introducedfor treating water supplyin rural areas. vii) The people to be educatedonsuch techniques through mass contact by usingmosquemedia,radio, televisionand other meansofmasscommunication.

References1. American Public Health Association. (1976)

“Standards methods for the examination ofwaterand Wastewater”, 14th ed.Washington.

2. “Water Borne Diseases-200Children beingadmitted daily to Pindi hospitals” The DailyDawn, 6 June, 1998 Pakistan.

Coliform (%) N Coliform L%)86 2 86.278.9 89 587 0 87.089.573 1

89.573.1

V

3

‘p

.4

38

3 “Doctors caution against spread of hepatitis,cholera”. The Daily Dawn, 13 July, 1998Pakistan.

4 Frazer, P , et al (1998) “Nitrate and humancancer,a reviewof theevidence” internationalJournal of Epidemiology

5 Ministry of Supply and Services, Canada(1978) “Guidelines for Canadian DrinkingWaterQuality”. Queebee.

6 Jsuess,M (1982) “Examination of Water forPollution Control. A Reference Handbook”PergammonPress,Derunark Vol. 1&2

7. Us EnvironmentalProtectionAgency (1976).“Quality Criteria for Water” Washington(ReportNo. 440/9-76-023)

8 WHO (1979) “Sodium, Chlorides andConductivity in Drinking Water”. WHORegional Office of the Europe, Copenhagen,(EURO reports)

9. WHO (1984). “Guidelines for drinking waterquality” Geneva Vol 1&2

39

SYNTHETIC INORGANIC ION-EXCHANGERS: EFFICIENTSCAVENGERS FOR TOXIC POLLUTANTS IN WATER

SyedMoosa HasanyNuclearChemistryDivision, PakistanInstituteof NuclearScience& Technology, P 0 Nilore, Islamabad,Pakistan

ABSTRACT Synthetic inorganic ion-exchangersare easy to prepare,siable towards heat and ionizingradianons,resistantto chemicalsandhave convenientpropertiesascomparedto their commercialorganiccounterpart They include hydrated metal oxides, acidic salts of polyvalent metals i e phosphates,

arscnaies,molybdatcs,tungslares,antimonaics,selenitesand vanadates,salts of heseropolyacidssuchasphosphomolybdates,tungstoarsenates,phosphosilicates,insoluble Ferro and ferricyanides,suiphidesandalkaline earthsulphates

They have been found to be very selectiveand efficient scavengersfor the removal of toxic metal ionsand organic pollutants presentin water They have been discussedin detail giving specific exampleswherethey can be successfullyutilized for the purification and decontaminationof water

IntroductionSynthetic ion-exchangersare superior to their

commercial organiccounterpartsdue to their easypreparationand low cost, stability towardsheatandionizing radiation, resistanceto acids, bases,organicsolvents, oxidizing and reducing reagents andcapacity over a wide rangeof acidity1° Becauseoftheir convenientchemical propertiesselectivity andefficiency, they havebeen extensivelyused in lastfour decades in Analytical Chemistry,Radiochemistry,EnvironmentalChemistry,NuclearTechnology, Hydrometallurgy and in metalrecovery, water purification and decontamination,and in nuclearand Industrialwastemanagement~2~

Applications of Inorganic Ion ExchangersThey have been utilized for the separation

preconcentrationof analyte element in order toremoveinterferencesor impuritiesand to achieveitsdetectionlimits before its actual measurementif itsconcentrationis below the detection limit of thatparticular analytical method to be used Moreover,these ion-exchangershavebeen employedto havecarrier-free production of radioisotopes asgenerators.They have beenapplied to achieve thedecontaminationof coolantwater in a reactorat hightemperatureand pressure They are useful in theremoval of radioactivity or radionuclidespresentinlarge volumes of water or to achievedecontaminationof vast areaof floors They havealso been employed successfully for waterpurification and decontamination They have alsobeen used for the desalination of highly salinewater They have beenused to processfresh andhighly radioactive fuel They have usefulapplications in the treatment and safe disposal ofnuclear and industrial liquid wasteinto waterwaysThey have been utilized for the purification andisolation of transuranic elements from highlyradioactive fission products in the spent nuclearfuel12~

Classificationof Ion-ExchangersThe inorganic ion-exchangersinclude hydrous

and non-hydrous metal oxides, acid salts ofpolyvalent elements i e phosphates, arsenates,molybdates, tungtates, antimonates, selenites andvanadates, salts of heteropolyacids likephosphomolybdates, tungstoarsenates, phospho-silicates, insoluble ferro and ferric-yanides,sulphides,and alkalineearthsulphates Sometypicalinorganic ion-exchangerswhich havebeenused arelisted in TableI

Table1. Syntheticion - ExchangersAntsnunaiesTi Cr Sn Ce,Ta

SeienitesTi, Sn

ArsenatesTi, Zr Sn

SuipindesFe, Cu, Ni, zn, As, Ag,Cd, Hg, Pb

FerrocyanidesTi, Mn, Fe, Cu, Ni, Cu, Zn, Zr Mn,Ag, Cd, w, Pb, Bi, u

SuiphatesCa, Sr. Ba

MnlybdatesTi, Cr, Zn, Sn

TungstatesTi, Cr, Ce

MOLYBDOPHOSPHATESLi, NH4. Na, K

TungntnphonphatesLi, NH,, Na, K

OxidesMg. At, Si, Ti, v, Cr, Mn, Fe,Zn, Zr,Nb, Mn, Ag, Sn, Sb, Ta, W, Ph, Th

vanadatesAt

PlinspltatesTi, Cr, Zr, Sn, Ta

Essentialand Toxic ElementsFor biological systems including plant and

animal life the elementscanbe classifiedinto twocategoriesi e essentialandnon-essentialelements.The essentialelementsperform essentialrole in aliving organism and their deficiency consistentlyresultsin the impairmentof a funcfion from optimalto suboptimallevel The essentialelementis presentin all healthy tissues of all living things Itswithdrawal from the body inducessome structuraland physiological abnormalities,its addition eitherremoves or prevent these aboormalities, Theabnormalities due to their deficiency alwaysaccompany pertinent and specific biochemicalchanges and these changes can be cured orprevented when this deficiency IS removed°1Another group of elements is known as toxicbecausetheir biological significance is confinedto

40

their toxic or potentially toxic properties atrelatively low concentrationsAll trace elementsaretoxic if ingestedor inhaledat sufficiently high levelsfor long enoughperiods Continuedingestionof dietor continuedexposureto total environmentthat areexcessivelyhigh in a particulartoxic elementinducechaiiges in the functioning, forms, activities orconcentrationof that elementin the body tissuesandfluids so that they rise abovethe permissiblelimitsIn thesecircumstancesbiochemicaldefectsdevelop,physiological functions are affected and structuraldisordersrise in ways which differ with differentelementswith the degreeand duration of toxicityand with the age, sex and speciesof the animalsinvolved (4) An element is said to be toxic if it

injures in the growth or metabolismwhen suppliedabove certain concentration.Toxicity is due to thebinding at non-bindingcenters or precipitationof ametal of the metalloenzymesand by the replacementof essentialelementsin the moleculesor enzymes.However, many clinical and pathologicaldisordersin the animals as a consequenceof the toxicelementsexcesscannotbe explainedin biochemicalor enzymatic term. Their toxicity above certainconcentrationlevel for biological systemshas beenproved. Theseelementsare Be, Hg, Pb, Cd, Cr,As, Sb, Se, Ti, U, Th and Pu Chromium seleniumand arsenic are among essential trace elementsHowever, their deleteriouseffects and toxicity onbiological systems have been proved in manyinstances.

Sourcesof Toxic ElementsThe major sourcesof toxic elementsand their

compoundsare listed (5) in Table-2 Becausethesetoxic elementsare harmful, their tolerancelimits inair, food and water have been identified Table-3gives the tolerance limits of these elements indrinking water (6) and their concentrationrangesmeasuredin freshwater~7~are very low as comparedto their tolerancelimits in drinking water except incase of lead where higher concentrationof leadfound in freshwater is quite close to its tolerancelimit in drinkmgwater.

Table2 Major Sourcesof Toxic Elementsand theirCompounds

Be Alloys, Ceramic and Refractory Products, RocketFuel, X-Ray Tubes, Electronic tndustry

Cr Stainless Steel, Chrome Plating, Non-Ferrous Alloys,Leather Tanning, Pnnting, Dyes, Pigments. Paints,Refractones, Wood Preservatives, Welding, Batteries,Catalysis

As Laser and Solid State Devicea, Herbicides, WoodPreservatives, Medicinal And Vetennary Uses, BottleGlass.Alloys Pigments,Textitle Printing,Taxidermy

Se Laser Technology, Xerography, Infrared Photography,PhotoelectricAnd SolarCells, StorageBatteriesRectifiers,Glass and Ceramic Industries, Pigments,Rubber,Lubricating Oils And Greases, Drugs and SpecialMedicines

Cd Electroplating, Pigments, Storage Batteries, Rubber,Paints, Plastics, Pigments, Semiconductors,Brazing and

Low-Melting Alloys, Welding, Fungicides andinsecticides,ReactorControl Rods

Sb SpecialAlloys, Pigments,Paints,SmallArms and Bullets,Storage Batteries, Semiconductors,Electronic Devices,Medicines, Cable Sheathing.Flame-ProofingCompounds,Glassand Pottery, Linotyping

Hg Fungicides, Dental Preparations, Electrical Apparatus.Industrial Control Instruments Dry Batteries. Paints.Pharmaceuticals,Explosives,Metal Plating

TI Corrosion Resistance Alloys, Electronic Equipment,Photoelectric Cells, Optical Systems, Fiberglass,Rodenticides,Insecticides

Pb Gasoline Additives. Ammunition, Metal Products, Paints,Pigments,StorageBatteries.GlassMaking, Plastics

Th NuclearFuel, GasMantlesU NuclearFuel, Research,Ceramic Glazes,AlloysPu NuclearFuel

Table3 ToleranceLimits of Toxic ElementsinDrinking Waterand their Concentrationin Fresh

WaterElement Tolerance

iitmtst61 ~i g L-’Freshwater

concentration~~tg L’Be - 001-iCr 50 01-6As 20-50 02-230Se iO 002-iCd 5-10 001-3Sb 10-23 001-5Hg 1 00001-28TI - -

Pb 50-100 006-120Th .

U 12 002-5Pu - -

Factors Controlling SorptionThe inorganic ion-exchangers due to their

superiority over commercially available ion-exchangershavebeenusedfor the removal of toxicmetal ions present at low concentrations Thesorption behaviour of these metal ions fromdifferent electrolytesunder experimentalconditionscanbe exploited to achievethis goal The sorptionof metal ions onto inorganicion-exchangersdependson many factors~8~suchas natureandcompositionofelectrolyte, its pH, temperature,equilibration timebetween sorbent and sorbate, presence ofcomplexing agents, anions and canons, iomcstrength,aging of sorptive solution andsorbentandconcentrationof metal ions, surfaceareaandotherpropertiesof sorbents.Theseparametershaveto beoptimizedto achievemaximumsorption

SpecificExamplesof Sorptionof Metal IonsIn Table 4 few specific examplesfrom current

literature are mentioned where inorganic ion-exchangerscan be used for the removal of toxicelementsfrom aqueoussolutions In column 2 and 3of this table sorptionand desorptionconditionshavebeen enumeratedFor exampleU(VI), Cr(IH) andSb(V) are sorbed almost quantitatively(iO) frombuffer solution of pH~6~onto tin oxide surfacewhereas these metal ions can be desorbed usingaqueousnitric acid solution Similarly, Cd(II) can

be sorbed(> 99%) from its very dilutesolution of

41

Table4 Ion-Exchangersas Scavengersfor Toxic Elements

0 001 M HC1 or H, SO4 onto sodiumtitanate22 The

sorbed cadmium can be removedfrom the surfaceusing comparatively concentratedsolution of 1 MHCI or H

7 SO4 Theseexamplesshow that toxicelements can be removed from aqueoussolutionsusinginorganicion-exchangerseffectively

ConclusionsIt can be concludedthat theseion-exchangers

may be usedfor the decontaminationor purificationof water. They can be utilized to separatetoxicelementsfrom their very diluted solutionsin water.They canalso be employedfor the removalof toxicelementsfrom industrial effluents before their safedisposalinto waterways.

References1 Pekarek and V. Vesdey (1972) Talanta

19(217) 1245(1972)2 Dearfield (1982) “lnorgamc Ion-Exchanges

Materials”, Florida CRC Press,Boca Raton.3. Eichorn (1973). “Inorganic Biochemistry”

Amsterdam.Elsevier4. hertz, FederalProceedings 29, 1482 (1970)5. Grayson(1979) Kivk Othmer Eweydoplkm of

ChemicalTechnology NewYork JohnWiley6. Reilley Metal ContaminationofFood”Applied

SciencePublishers,U.K. 19807. IHQ8. Benesand V Major (1980). “Trace Chemistry

of AqueousSolutions”.Amsterdam Edsevier9. Srivastava and C k. Jam (986). J. Radioanal.

Nucl. Chem 98 83-89.10. Bhattachai-yya,N C Dutta and A De (1990).

J Radzoanal.Nuci Chem 140: 121-131.

11 Bhutani, A.K Mitra and R. kumari (1992).Radiochim,Acta 56~153-158.

12 Namasivayam and K Ranganathan (1993)Environ. Poll. 82: 255-261

13 Mishra and V K Singh, Radiochim.Acta 68,(1995), 251-256

14 Ernhard, J. Radtoanal. Nucl Chem. 177,(1994)321-325.

15 Thanabalasingam and W F Pickering,Environ Poll. (B) 10, (1985), 115-118.

16. Gadde and H A. Laitmen, anal Chem. 46,(1974)2022-2026

17 Gascon, M.T Grespo and M. L. Acena(1990). J. Radioanla. Nucl. Chem. 139,. 249-254.

18 Song Yinjie, Zhang Hui, Li Fuhangand YangQuaolin (1995) J Radional Nucl. Chem 190155-166

19. Wong, G. S Brown and v E Noshkin(1978).J Radioanal NucI. Chem.42: 7-15

20 Hasany,A M Shamsiand M A Rauf (1997).Appi Radiat. isot. 48 595-600

21 Bhattacharyya and A De. (1986). J.Radioanal Nuci Chem 100: 277-285.

22 Misra, V. K. Singh and D Tiwari (1997).AppI. Radiat, Isot 48. 435-440

23 Mishra and Upadhyaya, S (1995) J.Radioanal.Nuci Chem. 189 247-256

24. Lieser andK. Medert (1995) Radiochim Acta68 191-195

25 Srivastava,G Bhattacharjee,S Kumar, C K.Oberoi and A. K Sharma(1980) J. ChemTech. Biotechnol. 30: 757-763.

Element Ion Exchanger AdsorptionConditions DesorptionConditions RefCr(iIi) tO’ M Iron Os~tde pl-1 6 5 - 9UO,”, Cr”, Sb” Tin Oxide 50 ml! g pH 6, 98 9%, 963%, 99 8%

(5ppectively(HNO, H,O) (I 3) 10

Cr(VI) 10’- 10’ M vanadium Oxide 48 mug pH 2, 90% IICr (IV) i-6 x 10’ M Fe(IiI)/ Cr011) Hydroside �l00% soTption pt-I 5 7 - 12CD(II) 10’ M Hydrous Ceric Oxide 92 1% from pH 1047 solution � 3% 13

ShO,’ AI,O, 99% 0 IM HNO, I M NH, 4

Hg (II) I 5 x 0’ M Manganese Dioxide 00% sorption at pH 6 I(X)% d4eSorption with 005 M EDTAsolution

IS

Ph(1I) 10’ M Ferric Oxide, ManganeseOxide, Aluniiniun Oxide 00ml! I) I mg

pH 8 00% 6

Th(IV) Manganese Dioxide 200nsl!250 ntg

pH 8 7 98% 17

UO,’ 10’ M Silica Gel-Titania mixed 190% pH 4-7 solution 18

Pu (IV) Manganese Dioxide pH 8- 0, 90% 19Se (IV) 7x10’-7x10’ M Titanium Oxide 45 mI!SO mg (101 M HCI, HNO,, HCIO, or

H,SO, � 99%. 20

Pb (II) Stanni,, Phosphate 99 2% at pH 6 5 . 2!

Cd(lI) 10’ M SodiumTilanate 00 mg!l0n,l 992% Irons 10’ M FtCI orH,SO,_or_pH_�_45 solution

IM HCI or H,SO, 22

Hg (II) 10’ 10’ M Potassiun,Titanate 974% from 0 I M O~alicAcid+_02_M_NaCI,_972%_aipH_65

- 23

Tb (IV) 10’- 10’ M Strontium Sulphate 972% (coin I M NaCI + 01 MH’SO,

- 24

Tl(l), Cd(Il), Pb(II)5x10’M

ChrontiumFerrocyanide 98, 98, 92 6% pH 2-3 T!(I) Desorbedwith 3 M mixture ofNH,NO,+ HNO,

25

42

WATER CHEMISTRY, QUALITY CONTROL BYELECTROCHEMICAL METHODS

Riaz AbmedNuclearChemistryDivision, PINSTECH, p o Nilore, Islamabad

ABSTRACT. Water is very good solvent It dissolvesuiost of the salts and substanceswhich cume incontactwith it and to propertiesvary accordingto the solutespresentin it Thus ionization of water, acidbase equilibria, solubility constants,common ion effect, secondarysalt effect, complexation, Redoxprocess,corrosionprocesses,chemicalkinetics,colloid and scaleformationetc all dependon thesolutespresentin water Before carrying out any processesof water purification and treatmentone has to takeinto considerationthe propertiesof the solutespresentand thesecan be well understoodanti explainedbyelectrochemicalmethods Most of the work in water purification, water sterilization, coagulation,filtration, screening, sedimentationetc involves solution chemistry For quality control of waterelecrroehemicaltechniquesare sensitive, reliable, cost- effective and can analyse a large numberofconstituentsof significant importance Metals and other toxic substanceshave been effectively removedby electro--deposition,eiectrodialysisand electro-oxidationfrom industrial waste water All types ofpollutantsfrom wastewater can he effectively removedusing electroehemicalreactors In power plantsscaleformation and water corrosionare most importani problemswhich are also electrochemicalinnature

IntroductionWater is the most important constituents for

human-life Without water life is not possiblebecauseof its essentialityfor life God hasprovidedthis on earthglobe in abudanceNearly threefourthof the earth globe consists of water Humanpopulationshave been concentratedin those areaswhere drinking water was available in abudanceNatural waters are never completely pure. Duringthereprecipitationand their passageover or throughthe ground they acquirea wide variety of dissolvedor suspendedimpurities This raw water must betreatedand purified before using for industrial anddrinking purposes1t1For proper treatmentof water,water chemistrymust be known, which means thedifferent constituentspresent in water and theirproperties m so1ution~21Due to industrialization alarge number of pollutants have been added intowater sources It is necessaryto do proper qualitycontrol of drinking and industrialwater for differentconstituents136~.

In this paper water chemistry is brieflydescribed water purification and treatment havebeenmentionedand water quality control havebeendiscussed It has been shown that electrochemicalmethods are simple, cost-effective, sensitive andreliablefor all purposes

ExperimentalVA processor646 Potentiograph536 and pH

meter 605 all from Metrohm, Switzerland,Polarographic analyzer 174A Electrochemistrysystem370from PrincetonApplied Research,USAwere used. Codonductivity meter used was fromWescan,USA.

All the chemicalsused wereof proanalysisgradefrom E-Merck, Germany

Trace metals were analysedusing differentialpulse anodic stripping voltammetry.Standardelectrochemical methods were used for all themeasurements.

ResultsandDiscussionsStudy about the behavior of different solutes

present in water is called water chemistry andmonitoring or analysis of different constituentsinwater is termedas quality control and thereis thirdaspectknown as water purification or treatmentandfor all of these three parameterselectrocheimcalmethods are most convenient, useful, reliable andaboveall cost- effective

WaterChemistryChemical substancesof interest range from

dissolved gasesthrough inorganic salts and othercompounds to complex organic materials, bothnaturaland synthetic,washedfrom fields andforestsand contained in municipal and industrial wastewaters. Water chemistry refers to the chemicalpropertiesof aqueoussolutions contaimnganyof thewide variety of substances,found as impurities innatural waters, addedto water during treatment,picked up in the flow of water or imposeduponwater through domestic, mumcipal or industrialuses

Water ionizes into acid and basic radicals andthus can dissolveboth types of substancesi e; acidas well as basic

H20 ~ H

4 + OH2H

2O ~ H~O~+ ORFor acidic substances

be given asH,CO3ty H

4 +HCO3 ________

HCO3 ~. H4 + COç ______

[HCO3I

For basiccompoundsionization constantsareNH3 +H2Oc~’NH4

4 + OFt K =INJJJJQLIJ[NH

3IAlkalinity of water is of paramountimportance

both for drinking and industrialpurposes.It may bebicarbonate,carbonateor hydroxidealkalinity.

ionization constants may

K = [Wi [HCOJ

1H2CO31K2 = 1H

41[CO~1

43

Thesecanbe calculatedby simplemethodP = PhenolphthahnealkalmityT = Total alkalinitya = PITIf a = 0, bicarbonatealkalinity = TIf a < 0.5 = (1-2a)TCarbonatealkalinity = 2aTIf a=0.5 = TIf a> 0.5 = 2(l-a)THydroxidealkalinity = (2a-1 )TIf a=1 = TSolubility constants(Pks) of some compounds

usedin water treatmentalongwith their applicationsare important.Pks of Al(OH)3 and Ca(OH)3 are32.9and 5.26 which are used for coagulation andsofteningrespectively(7)

Stability constantsof hydroxocomplexesusedforwater treatmentare also important. Both solubilityconstantsandstability constantscan be calculatedbyelectrochemicalmethods.

Dechlorination, deoxygenation, inorganicbiochemical metabolism have specific potentials(Table.1). Oxidation related to disinffection andodour control are also potential and pH dependent(Table-2) Water corrosion is also properlyexplained and understood by electrochemicalmethods(Table-3).

Water Treat,nentMajor problem in water treatmentis removal of

colloidal particles. Colloidal particles as a result oftheir small size have a very large ratio of surfaceareato volume. For example 1 Cm

3 of material ifdivided into cubes0.1mm on a side will have asurfaceareaof 0 06 m2, while if divided into cubesl0°mm on a side will havesurfaceareaof 600m2.Colloidal particles may be even smaller than 105mm Most colloidal particles in water and waste

water are negatively charged. The stationarychargedlayer on the surface is surroundedby abound layer of water in which ions of oppositechargesdrawn from bulk solution produce a rapiddrop in potential. This drop within the boundwaterlayer is called the stern potential, a more gradualdrop, called the zeta potential occurs betweentheshearsurfaceof the boundwater layer and the pointof electroneutrality in the solution. Stability ofcolloids depends on the magnitude of the zetapotential. Coagulation is a chemical techniquedirectedtowardsdestabilizationof colloidal particlesby usingpolyelectrolytes.

Sterilization] Disinfection of water is mostlydone by usingchlorineand this chlorineis producedby theelectrochemicaldecompositionof brine.

Quality ControlElectrochemicalmethodsarefrequentlyusedfor

the quality control of drinking and industrialwater.Mostly used electrochemical methods arepotentiometry, ion-selective electrodes,conductometry, polarography, voltammetry,strippingvoltammetryandcoulometry.

PotentiometryIn this techniquechangein potential is measured

for the determinationof different constituents Alarge numberof constituentscanbe measuredusingthis technique Some of the importantconstituentswhich are measuredin water by this techniqueare;pH, alkalmity, acidity, Aluminium, Silver, Aminocompounds,acetic acid, gold, bromme,boric acid,chloride, C1O

3, dO4, cyanide, copper, calciumcarbonate, carbonyl compounds, carboxyl acids,cerium, calcium, phosphate, EDTA, NTA,Mercury,Nickel and manyothers.

Table: 1: Dechlorination, Deoxygenazion,inorganic BiochemicalMetabolism

S.No. Reaction E°V Remarks

I S04 + 4H~+2e = H2S03+ H20 0 i72 Dechlorination,deoxygenation(4—)

2 SO4~+ 8H~+6e = S+4H20 0375 BacterialReduction(—)(-O 21 at pH 7)

3 S + 2H~+ 2e = H2S ~ 0 142 Sulfer bacteria(—~)-033 at pH 7

4 HNO2+7H* + 6e = NH4~+2H2O 086 Nitrification(—)0 38 atpH 7

5 NO~+H20÷2e = N02:+2’0H 0 01 Nitrification (4—) at p1-I 7

Table2. OxidationRelatedto Disinfectionand Odour Control

SNo. Reactuon E°V Remarks

1 O3+2H~+2e= 02+H20 2 07 Most powerful (—*)1 68 at pH 7

2 H202 + 2H~+2e = 2H20 1 77 1 26 at pH 7 (-÷)

3 MnO4+4H~-t-3e=MnO2+2H2O 1 68 Odor oxidation (—÷)113 at pH 7

4 HOCI+H~+2e=CF+H2O 1 49 1 28 atpll 7 (—*)

5 Cl2+2e = 2C1 i 358 (-3)

6 Ci02+e = C1O2 115 C102<HOCI (-+)

7 Br~+2e= 28r 1 087

8 OCF + 2H20+2e = C1+20H 0 88 0C1 oxidation (—3) at pH 14

4

44

Table3 Metallic Corrosion and CathodicProtection

SNo.1

Reaction E°V RemarksMg~+2e= Mg -2 37 Sacrificialanode (<—)

2 Al+**~l~3e= Al -1 67 Sacrificialanode(4—)

3 Zn~* +2e = Zn -0 762 Sacrificialanode(4—)

4 Fe~* +2e = Fe -O 409 Initial corrosion(4—)

5 Pb~* +2e = Pb -0 126 Initial corrosion(4—)

6 Cu** +2e = Cu 0 345 Initial corrosion(÷—)

7 Fe~~+e= Fe~ 0771 Ferousoxidation(+—)8 Fe(OH)

3+e= Fe(OH)2+0H -0 56 Rustformation (<—)

Ion-selectiveElectrodesThese are electrodes prepared for the

measurement of specific constituents. A largenumberof ion- selectiveelectrodesare available inmarket. Some of the commonlyused ion- selectiveelectrodes are Aluminium, Amlnoma, barium,bromide, cadnuum, calcium, carbon dioxide,chloride, cobalt, copper, cyanide, fluoride,fluoroborate, iodide, lead, lithium, magnesium,manganese,mercury, molybdate, nickel, nitrate,nitrite, perchlorate,phosphate,potassium,selenium,silver, sodium,strontium,sulfate, sulfide, telluride,thiocyanate,thiols, waterhardnessandzinc It maynot be possible to purchaseall the ion selectiveelectrodesand it is also not advisablebecausemanyof theseelectrodeshavea specific life period, butsome of the frequently used electrodesmay bepurchased

PolarographyPolarographyis very useful technique in which

potential is varied and the corresponding currentproduceddue to the reductionor oxidationof theanalyte is measured and the measuredcurrent isdirectly proportional to the analyte concentrationNow most of the elements and compounds bothinorganicandorganichavespecific redoxpotentialswhich canbe exploited for their analysis It canbeusedfor the analysisof heavyand toxic metalslike,nickel, cobalt, cadmium, lead, chromium, copper,zinc, tin, arsenic, selemum, molybdenum andaluminium It can also be used for the analysis ofpetroleum, mtrate, nicotine, fructose, org.compounds, nitnlotriacetic acid (NTA), EDTA,Vit C, 5, SO3, S203, cyanide, inorganic anions,quinine,ammoma,nitrite, styreneandmany others.

Stripping VoltammetryCoulometiy

In this technique the quantity of electricityrequired for an analyte to undergo a chemicalreaction is measuredwhich is proportional to theanalyteconcentration.This is a simple method forthe measurementof a large numberof constituentse.g;chloride,bromideIn this techniquethe anlyte tobe measuredis first preconcentratedelectrolyticallyon the electrodeand then current is measuredduringthe stripping process. In this way analyte can bepreconcentratedby morethan ten thousandstimesinthe electrodeas comparedto its concentrationin thesolution. This technique makes it possible tomeasuretrace metals in water upto the level of

lng/l A large number of trace metals can bemeasuredby this techniquewhich includecadmium,lead, copper, silver, mercury, selemum, iron,manganese, barium, bismuth, cobalt, cesium,nickel, cobalt, uranium, tin, zinc and many others,iodide, acids,nitrate, ammoma,uraniumetc.

ConductometiyConductivity is a measureof total dissolved

solids in waler. It is also used in ionchromatographyas a detectorsystem

Determinationofheavyand toxic metals (Cd, Pb,Cu and Zn) in drinking water.

A largenumberof water sampleswereanalysedfrom Rawalpindi and Islamabad area for thesemetals Sampleswere collected from Simly dam,Rawal dam, andalso many sampleswere collectedfrom specified areasof Rawalpindi and Islamabad.Well water andTubewell water sampleswere alsoanalysed.Values of Cd, Pb, Cu and Zn in surfacewater sampleswere in the ranges of 0 01 to 0.24j.tgIl, 2 4 to 14.2 pgIl, 1.2 to 4 3jig/l and from 4 39to 17.96 p.tg/l respectively.The valuesof Cd, Pb,Cu and Zn in ground water samples were m therangesof 0 08 to 0.38, 0.33 to 5.30, 0.56 to 4.93and 5 4 to 200~ag/lrespectively.All the values arewell within limits.

AnalysisofmineralwatersamplesSix types of mineral water samples were

collectedfrom the marketandanalysedfor differentconstituents.Valuesare given in Table-4.pH of allthe samplesis about8. Total hardnessandchloridecontentsof M1 sampleare high. Levels of calcium,magnesium, carbonates, sodium, potassium arewithin the permissiblelimits.

Removalof Pollutantsfrom WaterElectrochemicalmethodsare very good for the

removal of different pollutants from water18> Eco-

Cells are availablefor the removal of toxic metalsfrom industrial waste>9>. Electrodialysis has beenused for the removal of salts from water.Electrochemical reactors are available for theremoval of different pollutants from water~0~.Electrochemicalreactorsconsistof charcoalfilterskept at a certain electrochermcalpotential. Manyorganic toxic pollutants are reduced or oxidized atthosepotentialsinto non toxic compounds,whereasinorgamc ions are removed selectively byelectrochemicaldeposition These electrochemicalreactors can be regeneratedby reversmg theirelectrochemicalpotential.

45

Table 4: AnalysisofMineral Water Samples

Constituents M1 M2 M3 M4 M~ M6

pH 80 81 79 55 83 83

Conductivity 1959 760 487 823 403 524

T Hardness 624 232 226 386 i40 180

Ca-Hardness 300 116 112 300 12 24Mg Hardness 324 116 114 ~8 128 166Chloride 570 102 17 47 60 85Carbonates Nil 16 40 Nil Nil Ni!Bicarbonates 252 264 280 400 140 102

OH-Alkalinity 252 280 240 400 140 102Sodium 200 75 95 24 24 25Potassium 1 0 4 0 5 0 1 0 2 0 -

Sulfate 120 40 40 25 2 0 -

References

I American Water Works Association (1971)“Water quality and treatment A handbookofpublic water supplies”.Mc Graw-Hill

2 Riaz Ahmed (1997). “Water Chemistry”.Proceedingsof Training workshop on waterchemistryand quality control Feb 16-20, 1997,islamabad.

3. ASTM (1966) “Manual on Industrial wastewater”. ASTM Special Technical PublicationNo 148-1

4 ASTM (1981) “Annual book of ASTMstandards”.Vol--3 1

5 Riaz Ahmed; Roomina Tanwir and Qureshi,I H (1984) “ChemicalAnalysis of surfaceandground water of selected areasof Pakistan”Report.PINSTECH/NCD-107,1-44

6 Riaz Ahmed, et al (1998)Drinking and IndustrialNCD/P-116,1-30

7 Fair, G M., Gayer, J C and Okun, D A“Water andWaste Water Engineering” Vol.2NewYork. JohnWiley

8 Pletcher, D (1982) “IndustrialElectrochemistry”. New York ChapmanandHall

9 Riaz Ahmed. (1997) “Cost effective andsimple solutions of environmentalpollution byelectrochemicalmethods” Proceedingsof theNational Symposium on EnvironmentalPollution Feb 1997, Islamabad.

10 Smyth, W F ed (1980) “Electroanalysis inhygiene, environmental, clinical - andphermaceutical Chemistry” AmsterdamElsevier.

“Quality control ofwater” Report,

4

46

NITRATE POLLUTION IN DRINKING WATER AND ITS MEASUREMENT

needed

MuhammadManshaChaudhry,Tariq M. NaeemandAsmatullahPakistaninstitute of EngineeringandApplied Sciences,P 0 Nilore , Pakistan

ABSTRACT A rapid and accuratemethodbasedon ultraviolet muitiwavelengibabsorptiometi-y tor thedirectdeterminationof nitrate in natural and potablewaters is used After acquisitionot data tor sample

at 1 nni interval between205-250 nm, the proposed computationalproceduregives in a few secondstheconcentrationof nitrate The principle is to usea polynomial correctionfunction to cancelnumericallythe interferencesfrom suspendedand organicnianersand to resolvethe systemtorrned by the sumof theabsorbanceof nitrateand the interferencetuoenon Matrix calculationis madewith MATLAB® sottware.

the least squaresmethod minimizes the error betweenthe measuredabsorbanceand the model Thecharacteristicsof theUVMA methodsand the residual interterenceshavebeenevaluatedand comparisonwith the referencemethod has shownthat nitrate measurementby UVMA is a valuable tool for the fastandbr continuousmonitoring

4(2;) = ii,n(2,) + c/(2i) * ( /

Introduction is an infinite number of organic componentswe

The nitratepollution in water has increasedsince would need to identify and characteriseall of them1960w and excessive use of nitrogenousfertilizers to estimatetheir effect. Since this is not possible,havebeenblamedfor it But other factors such as an estimation of these interferences can bechanges in land use and recycling of sewage proposed,if we recognisethat all ultraviolet spectraeffluents in low land water although not large in of natural water or treated wastewaterwith lowPakistanmust also be considered nitrate concentrations have the same form a

It is well known that nitrate combines with featurelessand decreasingshape The choice of anhuman blood and forms methaeinoglobinemia>2>due estimationfunction is of great importanceand the

to which oxygen carrying capacity of blood bestadjustmenthasbeenobtainedwith a polynomialdecreasesand is mostly found in the bottle fed- functionchildren Excessnitrogen causeseutrophicationin So for each wavelength 2i, the measured

surface waters and alongewith phosphatescauses absorbanceA(2i) is the sumof two absorbances.algae growth Also, ingestednitrate is reduced inadult stomach and after reaction with secondaryaminesforms N- nitroso compoundsmost of which (1)arecarcinogenic

Many methodsare availablein the literature forthe determinationof nitrate Ion selectiveelectrode

Where A(2i) is the measuredabsorbancevalue

at the wavelength 2i, Arn(2i) the theoretical

method,althoughrapid, but hasthe limitations such absorbancevalue given by the sum of all theas poor sensitivity and numerousinterferences UV interfering speciesexcept the p componentsto betechniqueappearsto be ideal as many people are measured,and e>(X,) and C are respectively theusing it due to simplicity and speed inspite of absorptivity and the concentration of the jth

interferenceswhich have to be correctedby various componentat wavelength 2i (optical pathlengthisprocedures Interferences are not eliminated assumedto be 1 cm)completely by two wavelength method>2> because Mathematically, this methodis basedon the factregressionparametersvary from sample to sample that any function Am can be approachedby aand a calibration curve for each type of water is polynomialof q degrees From a numericalpoint of

view, the advantageof polynomial modellingof theIn the presentstudy UVMA methodproposedby function Am, is to replacea function which is the

0 Thomas13>has been utilized after interfacing of sumof an infinite numberof unknownfunctions byUV-1201 Spectrophotometer (Shimadzu, Japan) a defined number of known functionswith IBM PC Thismethodhas the advantagethat it

neither needs pretreatmentnor pre-separationofcomponents

(1,2,2~,2~, . .. ,2”) with a defined number ofunknown parameters (a

0, ar,. ,aq) theseparametersare in fact the polynomial coefficients

UV1~’IAPrinciple which will be calculated with the unknownThe main problemwith the previousmethodsis concentrations(C>, C2 ., C~)of the p components

the need to take into account the numerous to be measuredinterferencesin the regionof interest Turbidity due The program computes simultaneously theto colloidal and suspendedmatter and organic polynomial coefficients and the unknownmaterials are the main factors of featureless concentrationsof the componentsto be measured,ultraviolet spectraof water. If we assumethat there by solving the system

47

C~ =‘M

a0

KA(An))

M is the matrix

• .&ji(21) 1 21 .21”

..tp(An) I An Aif’

The system~3~gives as its solution the valuesof

the coefficients(a0, a1, . , a,~)and the concentrations

(C1, C2 , Cq) that minimise the differencebetween measured and computed values of theabsorbance,for each wavelength 2i in the leastsquaressense.

This method is very suitable for our purposebecausepolynomial restitution, with a degree 3,leads to a close approximationof the backgroundfunction.

ProcedureA UV-1201 (Shimadzu, Japan) spectro-

photometerhas beenusedfor this work Before thefirst measurement, the determination of the

absorptivitieswas carriedout on a 4 0 mg/i nitratestandardsolution (preparedwith KNO3 and distilledwater) The absorbancesof the standardsolutionwere measuredat 1 nanometer intervals between

(2) 205 and 250 nm and transferred to the computerprogramwritten in MATLAB ® for IBM personalcomputer (PC) (which calculates and stordsabsorptivitiesas data) The samplewasthendirectlyplaced into the 10 mm quartzcell without addingany reagentor pre-treatment,and the absorbancevalues were transferredand used as data in theprogram

The computation is as describedbefore (with a(3) polynomial of third degree for interference

elimination) with addition of the nitrateconcentration.The required time for the completemethod, from setting the cell to the result is about30s Another importantfeatureof UVMA is that it

needsno calibrationcurve.

DiscussionsFigure 1 curve A shows the typical

spectrumof samplecontainingnitrateandsuspendedmatterwhereascurve B is the spectrumobtainedbycalculating Am from the coefficient calculatedbythe said Matlab® program The differencebetweenthe two being the actualspectrumof nitratepresentin water. Also, it is clear from the spectrum that

UV absorptiondue to suspendedand orgamcmatteris significant at the wavelength 205-230 nm wherenitratemeasurementsareusually made.

0_sO

045

0.40

Ab.orb,nc,i 035

0.30

‘MM

Where

sl(2I)

sl(An)

0.55

A

4,

II

-f

WaAelength (micrometer)

0.24 0-25

Figure 1 (A) A typical UV spectrumof watersample(B) Computedspectrumofthe backgroundfunctionAm as

Am=a0 + a1X + a1X,2 + a

3A~3 (a

3= 4.372, a1 = -24273,a2 = -0005, a3 = 129035)

48

Table1. Comparisonofresultsb UVMAand ColorimetncReductionMethod

. UVspectrumwas not smoothsocould not be fitted properly

The validation of the UVMA method has beendonewith samplesof drinking water and wastewaterincluding surfaceandundergroundwatersof variousorigm and comparedwith the referencemethod(Colorimetric reduction method). All theconcentrationsfound are withm the World HealthOrganisation(WHO) limit of 50 mg/L as N03 (4)

The results obtainedby UVMA methodare in goodagreementwith those obtained by other referencemethod But in case of wastewaterthe resultsobtainedby UVMA are not satisfactoryand furthermvestigationis bemgdone

References1. Hussain, S D, Akram, W; Sajjad, M I and

Iqbal, M Z (1993) J Env & Anal Chem2(10). 5-10

2 StandardMethodsfor the Examinationof Waterand Waste waters, American Public HealthAssociation, 16th Ed. 1985

3. Thomas, S Gallot and N Mazas. (1998)FreseniusiAnal Chem 338 238-240

4. Water Analysis Hand Book, Hach Company,Loveland,Colorado,USA, 1997

S. No. Water Sample UVMA (mg/L) Colorhnetric (mg/L)1 Tube well nearNilore, Islamabad 0 19 ±0 01 0 22 Malal bridge site

i) with suspendedmatterii) After centrifugation

1 30±0 06

1 41±0 05

1 2

1 3

3 Standardadditionof NET to‘sample_2_(ii)

2 10 ±0 10

271±0162 126

4 WasteWater(PlEAS) *Large error in polynomialcoeff

2 4

49

ANALYSIS OF POTABLE WATER IN DERA GHAZI KHAN

RizwanHussainP 0 Box No 1331, PAEC, ISLAMABAD

Abdul MateenPakistanInstituteof Engineersand Applied Sciences,Islamabad

ABSTRACT Water usedfor daily life in D G Khan has been analyzed for estimation of totalhardness,chlorides,sulfates, silica and other relatedparameters Samplesof groundwater(tube wells),canalwaterand water supplied by the local administrationwere collected for thesestudies The results

show very high levels of hardnessand sulfate concentrationsin undergroundwater sources Totaldissolvedsolidsin canalwaterare appreciablylower thanthosefound in sub-surfaceWatersamples Theresultsare discussedwith referenceto the quality ofwaterfor drinking purpose

IntroductionWater for domesticpurposesshouldbe obtained

from a source representing a clean anduncontaminatedsupply and as far as possible itshouldbe freeof animal waste,vegetablematterandindustrial effluents. Normally good quality watershould be clear, colourless,odorless,well aerated,cool, soft and free from toxic pollutants,sedimentsand suspended matter~’2~ Although manyparametersaffect the quality of water, yet the pH,total hardness,temperature,turbidity, coliform andphenolsm certain casesmy form the basis for theselectionof a water body for humanconsumption~3~

This paper describessome of the results ofanalysiscarriedout on drinking watersamplestakenfrom within the main city of D G Khan Varioussamples for this purpose were collected fromundergroundsources, D G Khan canal and watersuppliedby the local administration

ExperimentalChlorides, alkalinity and total hardnesswere

determined employing titrimetry silica andphosphates were estimated by standardspectrophotometricprocedures.All the analyticalmethodsusedconformedto the ASTM specifiedandrecommendedprocedures(4)

ResultsandDiscussionThe results of analysis conductedon different

water samplesusedfor domesticpurposesin D GKhan are presented in Table-i All the watersamplesare slightly alkaline in nature Solubility ofaluminum is <1 ppm betweenpH 4-9, whereasmostof the iron is precipitatedout aroundpH-81561This suggestedthat thesewater sampleswould be

Table 1 Resultsof WaterAnalysis

relatively free of aluminum and iron impurities asvisible from the analysisdata Very high levels oftotal dissolved solids (TDS) particularly in subsurfacewater (1616 and 1577 ppm) could be as aresult of the prolonged stagnationof water comingfrom the hilly terrainsof Sulemanrange where thesedimentaryrocks are known to bear water havinghigh concentrationsof salts In addition to this, thehigh temperatureandlow annualprecipitation(<10inches/year) may also contribute to the highconcentrationof TDS The sandy limestone clayrich in carbonatesand bicarbonatesis the maincauseof hardnessin thesesamples171 However, therunning water collectedfrom the canalhas low levelof total hardness

Sulfateconcentrationsof 759 mg/I and 688 mg/Iin tube well water samples are higher than thepermittedconcentrationof 200 mg /1 ~ This couldbe due to the fact that the mostabundantmineral inthe D G Khan division is Gypsum Establishmentof a cement factory near D G. Khan city mayfurther strengthens the argument about the highconcentrationsof sulfates.However, water suppliedby the local administrationhas concentrationsofsulfates within the permissible range181, whichsuggeststhat water is chemically softened beforesupplying to the house holds As a result of thecalcareousnatureof the soil, silica content in thesewater samples in low171, Low levels of chloridespoint towards the presenceof ca and Mg salts asTDS with very small contribution from NaCI Asthis type of soil is mature with practically nophosphatebearingminerals,very low concentrationsof phosphatesweredetectedin thesewatersamples

Parameter Twa Twb Mca Mcb Cwa Cwb..21i! ~55 76 76 80 805TDS—mg/I 1616 1577 692 676 372 370THardmg/I 679 648 308 319 122 143SpCond ~iS/cm 1740 1590 810 - 894 240 363Alkalinity mg/I 188 181 181 178 100 106Chloridesmg/i 54 54 56 54 18 25

...~j1atesmg/I 759 688 i22 134 34 28Silicappm 160 164 154 39 57 81

~~psphaies ppm I 0 I 0 < 1 0 i 0 I 0 < 1 0,,~spPart Mg/I Nil Nil Nil Nil Nil Nil

Oil & Grease Nil Nil Nil Nil Nil Nil1w = Water from tube well, Mc = Water supplieuby the local adminisiration,

50Cw= Waier from D G Khan canal

No suspendedparticles were detected in thewatersamplesexceptin thosetakenformathe canal.This is the result of the erosion of sandy soil19>coming in contactwith water of D. g. Khan canaloriginating from Tunsabarrage There was no badodor,oil andgreasein thesewater samples.

The results of analysessuggestthat potablewaterin D G Khan city is very hard having high levelsof sulfates and TDS Maximum permissible levelsapprovedby the Environmental ProtectionAgencyof Pakistan are 200,500 and 200 mg/l for totalhardness.TDS andsulfatesrespectively~°>This hasresulted in stomachand kidney stone problems inthe city The cheapestremedy for softemng thishardwater is boiling before use. This has two foldadvantageof decreasingthe hardnessas well asremovingthe harmful bacteria

Low concentrationof chlorides in the potablewater suppliedby the local administrationmdicatedthat the public healthdepartmentis using a methodother than chlorinationfor the sterilization of waterIt may most probably be using the Lime-sodaprocessthat softens water besides steriIization~8)

This process precipitates out carbonates,bicarbonates and sulfates of calcium andmagnesium

Theseresults are beingpresentedwith a view tooutline the drinkmg water quality data obtained in

this limited study for information of audienceof theone day workshopon quality of drinkmg water.

ReferencesI Gyngell, E S. (1960) “Applied Chemistry for

Engineers” Edwards Arnold Publishers 3rded p 264

2 Friberg, L, Nordberg, G F. andVouk, V eds.(1980) “Handbook of Toxicology of Metals”New York . ElsevierPublishers

3 Kannan, K (1991) “Fundamentals ofEnvironmental Pollution” S Chhand &company , India, p. 248

4 ASTM (1983). “Annual Book of ASTMStandards” Vol. 13 01

5 Brownlow, A H (1979) “Geochemistry” N JPrenticeHall p.131

6 Dungan, PR (1975) “Chemistry andPollution”. Macmillan

7 Huribut, C.S (1992). “Dana’s Manual ofMineralogy” JohnWiley & Sons

8 Truvedi, R P and Raj, G.eds. (1992).“Encyclopedia of Environmental Sciences”.Akashdep Publishmg House, India, Vol 20,

p909. Subramanian, S (1987) J Geol, Soc. India.

29, 20510 EPA. (1994) “Standards on Safe Drinking

Water” letter No 2(43)193 dated 29th May1994

5!

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ABSTRACTS OF SELECTED PAPERS

CleanandSafeDrinking Waterfor AllMuhammadAkram Chughtai

Quality~Contro1of Drinking WaterMian MuhammadAslam

Parametersof WaterQualityDr. Iqbal H. Qureshi

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CLEAN AND SAFE DRINKING WATER FOR ALL

MuhammadAkram ChughtaiRAG Division, ServiceIndustriesLimited, Lahore

The main themeof this presentauonis to createan awarenessfor cleanand safe drinking water amongstthe peopleas contaminatedwater may lead to many health problems This papercovers the introduction towater purification systems, its different stages,materials used and their suitability including the processofpurificationitself Amongst the materials,aclivatedcarbonis consideredto be very importantcomponent.It’spropertieswith referenceto it’s use in water purification systemssuch as bulk density, ash contents, CTCvalve, mesh size and hardnesshave beendiscussed Brief discussionon various disinfectantsused in thepurification systems to distroy the micro-organismsresponsiblefor quality deterioration has also beenmentionedat the end

QUALITY CONTROL OF DRINKING WATER

Mian Muhammad AslamWaterQuality Control Unit, CapitalDevelopmentAuthority (CDA), Islamabad

Significanceof water testinghasbeenhighlightedwith referenceto Islamic IdeologyandWHO guidelines.For the operationand maintenancecontrol of a water-supplysystemcritical parametertesting strategy hasbeen preferred over less frequent lengthy testings A brief account regarding the water borne diseasesemanatingfrom the pathogensas well as from the inorganicshas been.It hasbeenrecommendedthat sanitaryinspection should take preference over analysis for the assessmentof risk to human health due tocontaminationIt hasbeenelaboratedthat theCDA usesthe conventionalmethodsof coagulation,flocculation,sedimentation, filtration and disinfection for the preparation of potable water For the oxidation anddisinfection purposesliquefied chlorine is used The major sourceof surfacewater for lslamabadis SimlyDam Ground water is obtainedfrom the tubewells installed in the National Park area,and the spring waterfrom the Saidpur,Noorpur andShahdara-hillsprings Finally a note explainingthe reasonsof pollutedwatercomplaintshasbeenadded

PARAMETERS OF WATER QUALITYIqbal H. Qureshi

PakistanInstituteof NuclearScience& Technology,lslamabad

Wateris the mostessentialcomponentof all living things and it supportsthe life process Without water it

would not havebeenpossibleto sustainlife on this planet The total quantityof water on earth is estimatedtobe 1 4 trillion cubic meter. Of this less than I % water presentin rivers and groundresourcesis availabletomeet our requirements Theseresourcesare being contaminatedwith toxic substancesdue to ever increasingenvironmentalpollution To reduce this contaminationmany countries have establishedstandardsfor thedischargeof municipal and industrialwasteinto water streams

54

RECOMMENDATiQN~,~ ~

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RECOMMENDATIONS

The workshopfeelsthat there is a general lackof awareness in the masses regarding thediseases and ailments associatedwith poorquality of drinking water. It is therefore,recommendedthat a national level campaignshould be launched through mass media tocreate general awareness in the publicDifferent NGOs and the Governmentagenciesshould work together to create generalawarenessthrough trainings, workshops andoutreachprogrammes.

2 This workshopnotice that thoughvarioushealthproblems have emanateddue to use of poorquality water yet country has not adopteddrinking water quality standards.It is stressedthat these standards should be developedimmediately and enforcedin accordancewiththe Pakistan Environmental Protection Actpassedby the Parliamentin December,1997.

3. Pakistanhas witnesseda modestgrowth in themineral and naturalwater supplymdustry in thecountry over last few years.However, most ofthe individual industries are not processingandbottling water according to guidelines andstandardsset by WHO or national standards.This workshop, therefore,stressesthe necessityto standardizeall proceduresand the techniquesto process and bottle mineral/natural waterbefore marketing. The source of such watershould also be properly assessedand certifiedby an authorizedagency.

4 This workshoprecommendsthat a federalwaterquality monitormg and licensing agencyshouldbe establishedwith a mandateto monitor thequality of drinking water and to ensureimplementationof water quality standardsin thepublic as well as private sector. This agencymay be mandated:

(a) to set up guideline values for waterquality standardsin Pakistanwhich maybe updatedtime to time on the basis ofcontinuousresearchand monitoring;

(b) to set up standard procedures andtechniques for operation, maintenanceand certification for quality testing

PCPP1—2436(99)PCRWR—i7-4-99-—30~J

laboratoriesin respectof water treatment,potable water marketing, and qualityassessment;and

(c) to establisha panel of laboratorieswhichmay act as nucleusfor standardizationofproceduresrequired for quality controland quality assuranceof drinking water.

6 It is generally observedthat Municipal WaterSupply in Pakistan,even in big cities, doesnotmeetthe WHO or any other laid standards.Dueto poor maintenancepractices a pipe lines atplacesget damagedand result in getting mixedwith the nearby leakingseweragewater. It isrecommendedthat stepsshould be undertakento ensure that Municipal authorities undertakeperiodic randomcheckingof water quality andtake appropriateremedial measuresto ensurequality of the drinking water that reachestheend users.

7. The contammationof water drawn from wells,hand and otherpumpsetc. is very commondueto presenceof nearby septic tanks and pitlatrines in the rural areasandsmall towns. Theproblemneedsto be studiesin detail to arrive atappropriatedesigns 6,f the whole system inorderto geL contamination~freedrinking water.

8. This workshop recommends that simpleprocedures and techniques such as simplechlorination should be used for disinfection ofdrinking water stored in underground andoverheadtanks. People to be educatedon suchtechniquesthroughmasscontact.

9 Standards water quality analysis laboratoriesshould be established in all provincial andDivisional Headquarters.There is an urgentneed of a central well-equipped laboratory,which will act as thecertification laboratoryforall other laboratoriesavailablein the country.

Dr Bashir A. ChandioChairman,Pakistan

Council of ResearchinWaterResources

Sd/- Sd/-Dr. Din MuhammadSecretary,Workshop

OrganizingCommittee

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