STP_NRCD_Guidelines

8/10/2019 STP_NRCD_Guidelines

1/23

ReportCode:003_GBP_IIT_EQP_S&R_02_Ver1_Dec2010

Sewage

Treatment

in

Class

I

Towns:

RecommendationsandGuidelines


2/23


2|P a g e

Preface

In exercise of the powers conferred by subsections (1) and (3) of Section 3 of the

Environment (Protection) Act, 1986 (29 of 1986), the Central Government has

constituted

National

Ganga

River

Basin

Authority

(NGRBA)

as

a

planning,

financing,

monitoring and coordinating authority for strengthening the collective efforts of the

CentralandStateGovernmentforeffectiveabatementofpollutionandconservationof

the river Ganga. One of the important functions of the NGRBA is to prepare and

implementaGangaRiverBasin:EnvironmentManagementPlan(GRBEMP).

AConsortiumof7Indian InstituteofTechnology(IIT)hasbeengiventheresponsibility

of preparing Ganga River Basin: Environment Management Plan (GRB EMP) by the

Ministry of Environment and Forests (MoEF), GOI, New Delhi. Memorandum of

Agreement

(MoA)

has

been

signed

between

7

IITs

(Bombay,

Delhi,

Guwahati,

Kanpur,

Kharagpur,MadrasandRoorkee)andMoEFforthispurposeonJuly6,2010.

This report is one of the many reports prepared by IITs to describe the strategy,

information, methodology, analysis and suggestions and recommendations in

developingGanga RiverBasin: EnvironmentManagementPlan (GRB EMP). The overall

FrameWorkfordocumentationofGRBEMPandIndexingofReportsispresentedonthe

insidecoverpage.

Thereare

two

aspects

to

the

development

of

GRB

EMP.

Dedicated

people

spent

hours

discussingconcerns,issuesandpotentialsolutionstoproblems.Thisdedicationleadsto

the preparation of reports that hope to articulate the outcome of the dialog ina way

that is useful. Many people contributed to the preparation of this report directly or

indirectly.Thisreportisthereforetrulyacollectiveeffortthatreflectsthecooperationof

many, particularly those who are members of the IIT Team. Lists of persons who are

membersoftheconcernedthematicgroupsandthosewhohavetakenleadinpreparing

thisreportaregivenonthereverseside.

DrVinod

Tare

ProfessorandCoordinator

DevelopmentofGRBEMP

IITKanpur


3/23


3|P a g e

TheTeam

1. AAKazmi,IITRoorkee [email protected]

2. AKGupta,IITKharagpur [email protected],[email protected]

3. AKMittal,IITDelhi [email protected]

4. AKNema,

IIT

Delhi

[email protected]

5. AjayKalmhad,IITGuwahati [email protected]

6. AnirbanGupta,BESUShibpur [email protected]

7. ArunKumar,IITDelhi [email protected]

8. GJChakrapani,IITRoorkkee [email protected]

9. GazalaHabib,IITDelhi [email protected]

10. HimanshuJoshi,IITRoorkee [email protected]

11. InduMehrotra,IITRoorkee [email protected]

12. IMMishra,IITRoorkee [email protected]

13. LigyPhilip,IITMadras [email protected]

14. MMGhangrekar,IITKharagpur [email protected]

15. MukeshDoble,IITBombay [email protected]

16. PKSingh,

IT

BHU

[email protected]

17. PurnenduBose,IITKanpur [email protected]

18. RRaviKrishna,IITMadras [email protected]

1 9 . RakeshKumar,NEERINagpur [email protected]

20. SMShivnagendra,IITMadras [email protected]

21. SaumyenGuha,IITKanpur [email protected]

22. Shyam RAsolekar,IITBombay [email protected]

23. SudhaGoel,IITKharagpur [email protected]

24. SuparnaMukherjee,IITBombay [email protected]

25. TRSreekrishanan,IITDelhi [email protected]

26. VinodTare,IITKanpur [email protected]

27. VivekKumar,IITRoorkee [email protected]

LeadPersons1. VinodTare,IITKanpur

2. LigyPhilip,IITMadras

3. AAKazmi,IITRoorkee

4. PurnenduBose,IITKanpur

5. ArvindKNema,IITDelhi

6. AtulMittal,IITDelhi

7. Arun

Kumar,

IIT

Delhi

8. InduMehrotra,IITRoorkee

9. SubrataHait,IITKanpur


4/23


4|P a g e

Contents

SNo. PageNo.

1

General

5

2 SelectionofAppropriateSewageTreatmentTechnology 5

3 TreatmentChain 6

4 CostofTreatmentandLandRequirement 7

5 DecisionMatrix.. 7

6 SludgeManagement.. 13

7 FlowMeasurement. 13

8 BioassayTest 13

9

References

16

AppendixI.ExhibitsonOptionsforSecondaryTreatment 17


5/23


5|P a g e

1. GeneralSewage is a major point source of pollution. The target of Nirmal Dhara i.e. unpolluted

flowcanbeachieved ifdischargeofpollutants intheriverchannel iscompletelystopped.

Also,sewagecanbeviewedasasourceofwaterthatcanbeusedforvariousbeneficialuses

includingground

water

recharge

through

surface

storage

of

treated

water

and/or

rain/flood

waterinanunlinedreservoir.ThismayalsohelpachievingAviralDhara.

Inordertoreducesubstantialexpenditureonlongdistanceconveyanceofsewageaswellas

treated water for recycling, decentralized treatment of sewage is advisable. As a good

practice,manysmallsewagetreatmentplants(STP)shouldbebuiltratherthanafewofvery

largecapacity.Allnewdevelopmentsmustbuildinwaterrecyclingandzeroliquiddischarge

systems. Fresh water intake should be restricted only to direct humancontact beneficial

uses of water. For all other uses properly treated sewage/wastewater should be used

wherever

sufficient

quantity

of

sewage

is

available

as

source

water

for

such

purposes.

All

newcommunitysanitationsystemsmustadoptrecyclingoftreatedwaterforflushingand

completely isolate fecal matter until it is converted into safe and usable organic manure.

The concept of decentralized treatment systems and water/wastewater management will

becoveredindetailinsubsequentreports.

2. SelectionofAppropriateSewageTreatmentTechnologyItem4.5.2inGuidelinesforthePreparationofUrbanRiverManagementPlan(URMP)forall

Class I Towns in Ganga River Basin (Report No. 002_GBP_IIT_EQP_S&R_01) concerns with

sewage treatment plant. One of the most challenging aspects of a sustainable sewage

treatmentsystem(eithercentralizedordecentralized)designistheanalysisandselectionof

the treatment processes and technologies capable of meeting the requirements. The

processistobeselectedbasedonrequiredqualityoftreatedwater.Whiletreatmentcosts

are important,other factorsshouldalsobegivendueconsideration.For instance,effluent

quality,processcomplexity,processreliability,environmentalissuesandlandrequirements

shouldbeevaluatedandweightedagainstcostconsiderations.Importantconsiderationsfor

selectionofsewagetreatmentprocessesaregiveninTable1.

Table1:

Sewage

Treatment

Process

Selection

Considerations

Consideration Goal

Quality ofTreatedSewage Productionoftreatedwaterofstipulatedqualitywithoutinterruption

Powerrequirement Reduceenergyconsumption

Landrequired Minimizelandrequirement

CapitalCostofPlant Optimumutilizationofcapital

Operation&Maintenancecosts Lowerrecurringexpenditure

Maintenancerequirement Simpleandreliable

Operatorattention Easyto understandprocedures

Reliability Consistentdeliveryoftreatedsewage

ResourceRecovery Productionofqualitywaterandmanure

LoadFluctuations

Withstand

variations

in

organic

and

hydraulic

loads


6/23

6|P a

3. TAllsew

chosen

perthe

Specifi

StageI

a)Thre

b)Aera

followi

Expect

No

Pro

StageII

treatm

a) Po

b) Ac

bu

m

c) M

e

eatmeagetreatm

andthe tr

flowsheet

ationsand

PreliminareStageScr

tedGritC

gunitope

deffluent

floatingma

percollecti

Primarya

nt. These

dBasedS

ivated Slu

not limit

de(EAAS

mbraneBi

tChaientplants

eatmentc

presented

Figur

treatment

Treatmenening: 2

1

5

amber if f

rationisan

qualityafte

terialsincl

onand

dis

d/orSeco

optionsca

stemsor

ge Proces

d to SBR,

),ASPwith

Reactor(

shouldfoll

pacity. In

inFigure1.

1: Proc

objectives

t:

mmbarr

2mmbarr

mmmesh

llowingun

aerobic.

rprelimina

dingpolyt

osalof

scr

daryTrea

begroup

s (ASP) an

UASB foll

Biological

BR)

waproce

eneral, tr

ssChainf

teachsta

cks(befor

acks

(


7/23


7|P a g e

Expectedeffluentqualityafterprimaryandsecondarytreatment:

BOD


8/23


8|P a g e

country should not be construed as showing technological limitations, nor to affirm that

plants outside thatrange do not exist. The ranges simply indicate most frequently found

sizes. A comparison of treatmentcosts and evaluation of various technologies for sewage

treatmentinIndiaispresentedinTable2.

In

general

it

is

accepted

worldwide

that

the

technologies

which

are

deemed

to

be

appropriatehavetobequalifiedthroughapplicationofarigorousframeworkunderscoring

the performance expectations as well as the choice should be concurrent with the socio

economicacceptability.

TreatmentPlantFootprint,m2/MLD

Figure2: TreatmentCost(asin2010)andCorrespondingPlantFootprintforvarious

SecondaryTreatment

Options

TreatmentCost,

/kL

TreatmentuptoTertiaryLevel

TreatmentuptoSecondaryLevel

For Treatment Capacity > 100 MLD:

ASP EA - ASP UASB + ASP SBR

ASP + BNR MBBR MBR WSP

Treatment Plant Footpri nt, m2/ MLD

0 200 400 600 800 1000 1200 5700 6000 6300

0

2

4

6

8

12

15

18

21

24

27

ASP EA - ASP UASB + ASP SBR

ASP + BNR MBBR MBR WSP

For Treatment Capacity < 5 MLD:

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500

TreatmentCost,

/kL

0

2

4

6

8

10

12

ASP

MBBR

SBRUASB+EA

MBR

WSP


9/23

ReportCode:003_GB

9|P a g e

Table2:ComparisonofTreatmentCostsofVariousTechnologiesforSewageTreatmen

S.No. AssessmentParameter/Technology ASP*,a

MBBR*,c

SBR*,a

UA

1.0 PerformanceafterSecondaryTreatment

1.1 EffluentBOD,mg/L


10/23

ReportCode:003_GB

10|P a g e


MBBR*,c

SBR*,a

UASB+ASP*

5.0 Operation&MaintenanceCosts

5.1 EnergyCosts(PerMLD)

5.1.1Avg.TechnologyPowerRequirement,kWh/d/MLDSecondaryTreatment+SecondarySludgeHandling

180.00 220.00 150.00 120.00

5.1.2

Avg.TechnologyPowerRequirement,kWh/d/MLD

Tertiary

Treatment

+

Tertiary

Sludge

Handling 1.00

1.00

1.00

1.00

5.1.3Avg.NonTechnologyPowerReq.,kWh/d/MLDSecondaryTreatment

4.50 2.50 2.50 4.50

5.1.4Avg.NonTechnologyPowerReq.,kWh/d/MLDTertiaryTreatment

0.20 0.20 0.20 0.20

5.1.5 TotalDailyPowerRequirement(avg.),kWh/d/MLD 185.70 223.70 153.70 125.70

5.1.6DailyPowerCost(@ 6.0perKWh),`./MLD/h(IncludingStandbypowercost)

46.43 55.93 38.43 31.43

5.1.7 YearlyPowerCost,`.lacspa/MLD 4.07 4.90 3.37 2.75

5.2 Repairscost (PerMLD)

5.2.1 CivilWorks perAnnum,as%of CivilWorksCost 3.00 3.00 3.00 3.00

5.2.2 E&M Works, as%ofE&MWorksCost 1.00 1.00 1.00 1.00

5.2.3 CivilWorksMaintenance,`.Lacspa/MLD 1.94 1.30 1.04 2.11

5.2.4

E&

M

Works

Maintenance,

`.

Lacs

pa/MLD

0.43

0.65

0.81

0.38

5.2.5 Annualrepairscosts,`.Lacspa/MLD 2.38 1.94 1.84 2.48

5.3 ChemicalCost(PerMLD)

5.3.1RecurringChemical/PolymerCosts,`.Lacspa/MLDSecondaryTreatment

0.40 0.40 0.40 0.40

5.3.2RecurringChemical,`.Lacspa/MLD(Alum,Chlorine,Polymer)Costs,TertiaryTreatment

4.00 4.00 2.00 5.00

5.3.3 OtherChemicalCost,`.Lacspa/MLD 0.90 0.90 0.90 0.90

5.3.4 TotalChemicalCost,`.Lacspa/MLD 5.30 5.30 3.30 6.30

5.4 ManpowerCost(Assuming50MLD Plant)

5.4.1 Manager,`.pa(1No.) 3.60 3.60 3.60 3.60

5.4.2 Chemist/Engineer,`.pa (1No.) 3.60 3.60 3.60 3.60

5.4.3 Operators,`. Pa (@`.12000pm) 8.64 5.76 4.32 8.64

5.4.4 Skilledtechnicians,`.pa (@`.10000pm) 7.20 4.80 3.60 7.20

5.4.5 Unskilledpersonnel,`.pa (@`.7000pm) 5.04 2.88 2.16 5.04

5.4.6 TotalSalaryCosts,`.Lacspa 28.08 20.64 17.28 28.08

5.4.7 Benefits(50%oftotalsalary),`.Lacspa 14.04 10.32 8.64 14.04

5.4.8 Salary+Benefits,`.Lacspa 42.12 30.96 25.92 42.12

5.4.9 TotalannualO&Mcosts,`.Lacspa 629.26 638.11 451.22 618.96


11/23

ReportCode:003_GB

11|P a g e


MBBR*,c

SBR*,a

UASB+EA*,b

6.0 NPV(2010)ofCapital+O&MCostfor15years, .Lacs 14838.92 14971.67 12518.32 14684.42

Present(2010)TreatmentCost,paisa/L 0.54 0.55 0.46 0.54

7.0AverageCapitalCost, .Lacs/MLDuptoSecondaryTreatment

68.00 68.00 75.00 68.00

7.1

Yearly

Power

Cost,`.

lacs

pa/MLDuptoSecondaryTreatment 4.04 4.87 3.34 2.73

7.2AnnualRepairsCost,`.Lacspa/MLDuptoSecondaryTreatment

1.50 1.22 1.16 1.56

7.3AnnualChemicalCost,`Lacspa/MLDuptoSecondaryTreatment

0.85 0.85 0.85 0.85

7.4ManpowerCost,`. Lacspafor50mldplantuptosecondarytreatment

33.70 24.77 20.74 33.70

7.5TotalAnnualO&MCosts,`.LacspauptoSecondaryTreatment

353.02 372.11 288.15 290.72

7.6NPV(2010)ofCapital+O&MCostfor15years,`.LacsuptoSecondaryTreatment

8695.35 8981.58 8072.24 7760.85

7.7Present(2010)TreatmentCost,paisa/LuptoSecondaryTreatment

0.32 0.33 0.29 0.28

SludgeTreatment: *Thickener+Centrifuge; **Drying

ProcessType :aAerobic;

bAnaerobicAerobic;

cAnoxic/AnaerobicAerobic

1. NoSludgeDryingBeds. Howevercanbeprovidedtocater25%of

sludgedewateringunderemergencyconditions

2. NoFPUafterUASB,onlyExtendedAeration(EAProcess)

3. UASBnotRecommendedforinfluentSO4>25mg/L

4. NoBiologicalPhosphorusRemoval,Coagulantsarenecessary

5. NoEnergyRecoverysystemrecommendedonlyifBOD


12/23

ReportCode:003_GB

12|P a g e

Exhibit1: AssessmentofTechnologyOptionsforSewageTreatmentintheGangaRiv

Criteria ASP UASB+ASP SBR MBBR

Performance in Terms o f Quality of Treated Sewage

Potential of Meeting the RAPs TSS, BOD, and COD Discharge Standards

Potential of Total / Faecal Coliform Removal

Potential of DO in Effluent

Potential for Low Initial/Immediate Oxygen DemandPotential for Nitrogen Removal (Nitrification-Denitrification)

Potential for Phosphorous Removal

Performance Reliability Impact of Effluent Discharge

Potential of No Adverse Impact on Land

Potential of No Adverse Impact on Surface Waters

Potential of No Adverse Impact on Ground Waters

Potential for Economically Viable Resource GenerationManure / Soil Conditioner

Fuel

Economically Viable Electricity Generation/Energy Recovery

Food

Impact of STP

Potential of No Adverse Impacts on Health of STP Staff/Locals

Potential of No Adverse Impacts on Surrounding Building/Properties

Potential of Low Energy Requirement

Potential of Low Land Requirement

Potential of Low Capital Cost

Potential of Low Recurring Cost

Potential of Low Reinvestment Cost

Potential of Low Level of Skill in Operation

Potential of Low Level of Skill in Maintenance

Track Record

Typical Capacity Range, MLD All Flows All Flows All Flows Smaller

Low Medium High Very High

ASP :ActivatedSludgeProcess

MBBR :MovingBedBiologicalReactor

SBR :SequentialBatchReactor

UASB :UpflowAnaerobicSludgeBlanket

EA :ExtendedAeration

MBR :MembraneBioReactor

WSP :WasteSt


13/23


13|P a g e

6. SludgeManagementThe sludge dewatering should be done using thickener followed by filter press or

centrifugeoranyotherequivalentmechanicaldevice.Sludgedryingbeds (SDB)should

be provided for emergency only. SDBs should be designed only for 25% of the sludge

generated

from

primary

and

secondary

processes.

The

compressed

sludge

should

beconverted into good quality manure using composting and/or vermicomposting

processes. Energy generation through anaerobic digestion of sludges in the form of

biogas and subsequent conversion to electrical energy as of now is viable only when

sewageBOD>250mg/L.Singlefuelenginesshouldbeusedforconversionofbiogasto

electrical energy. Hazardous sludge, if any should be disposedof as per the prevailing

regulations.

7. FlowMeasurementFlowmeasuringdevicesshouldbeinstalledaftertheStageITreatmentaswellasatthe

outlet

of

the

sewage

treatment

plant.

These

flow

devices

should

be

of

properly

calibratedVnotchwith arrangements for automaticmeasurement of head. Additional

electronicorothertypeof flowmetersmayalsobe installed.Arrangementsshouldbe

madeforrealtimedisplayofmeasured(bothcurrentandmonthlycumulative)flowsat

prominentplaces.

8. BioassayTestThe bioassay test is gaining importance in wastewater treatment plant design and

operationasthewholeeffluenttoxicity(WET)test.Thistestusesastandardspeciesof

aquatic

life

forms

(like

fish,

algae)

as

a

surrogate

to

measure

the

effect

of

the

effluent

on

the receiving stream. The flowthrough method employing continuous sampling is

recommendedforonsitetests.

Flowrate(retentiontime):Foraflowthroughsystem,theUSEPAManualforAcute

Toxicity Test of Effluents (USEPA, 2002) specifies that the flow rate through the

proportionaldilutormustprovideforaminimumoffive90%replacementsofwater

volumeineachtestchamberevery24h(i.e.aretentiontimeof4.8h)(seeFigure3).

This replacement rate should provide sufficient flow to maintain an adequate

concentration of dissolved oxygen (DO).This impliesa maximumHRTof 5.3 h (i.e.

0.9V/Q

=

4.8)

for

a

flowthrough

system.

Therefore,

a

flowthrough

pond

with

a

maximum HRT of 5 h for 100% exposure is recommended for bioassay test of

tertiarytreatedeffluent.

Totalflowrequirement:10%oftheflow(subjectedtomaximum1MLD)isrequired

topassthroughthebioassaypond.


14/23


14|P a g e

Figure3:Approximatetimesrequiredtoreplacewaterintestchambersinflowthroughtests

(For Example: For a chamber containing 4 L, with a flow of 2 L/h, the above graph

indicatesthat90%ofthewaterwouldbereplacedevery4.8h.Thesametimeperiod,

suchashours,mustbeusedonbothaxes,andthesameunitofvolume,suchasliters,

mustbeusedforbothvolumeandflow(AdaptedfromUSEPA,2002)

Depthofflowthroughsystemorpond:Thedepthoftheflowthroughbioassaypond

shouldbe

within

1.5

to

2.5

m

based

on

an

equivalent

system

of

wastewater

fed

fish

pond(aquaculture)(CostaPierce,1998;HoanandEdwards,2005).

Testorganisms:Inthebioassaypond,locallyfoundfish,algaeanddaphniashouldbe

inhabited in the bioassay pond. USEPA (2002) and APHA et al. (1995) have

recommended following freshwater fishspecieswhen fish is thepreferred formof

aquaticlife/testorganism:

1. Oncorhynchusmykiss(rainbowtrout)andSalvelinusfontinalis(brooktrout)

2. Pimephalespromelas(fatheadminnow)

3. Lepomismacrochirus(Bluegillsunfish)

4. Ictalurus

punctatus

(Channel

catfish)

Based on above, following equivalent fish species are recommended under Indian

conditions.

1. Puntiasstigma

2. Puntiassophore

3. Anabas

4. Chelabacalia

5. Puntiastictoand

6. Colisafaciatus

1

10

100

0.1 1 10 100

TimeforPartialReplacement,Hours

Volume of Water in Tank / Flow of Water per Hour

99% Replacement 95% Replacement 90% Replacement

75% Replacement 50% Replacement

0.4

4

40

4 40


15/23


15|P a g e

Other freshwater fish species like Gambusia affinis (mosquito fish) can also be

considered.DaphniapulexandD.magna(daphnids),Selenastrumsp.,Scenedesmus

aculeala, Scenedesmus guadacanda are also recommended similar to the

recommendationsmadebyUSEPA(2002)forbioassaytest.

Stocking

density

and

number

of

test

organisms:

For

flowthrough

tests,

the

live

weight of test organisms in the systemmust not exceed7.0 g/L (i.e. 7.0 kg/m3) of

volumeat l5C,or2.5g/L (i.e.2.5kg/m3)at25C (USEPA,2002).Aminimumof20

organismsofagivenspeciesarerequiredforthetest.

Feeding requirement: Considering the bioassay of tertiarytreated sewage effluent

andfishasthepreferredformofaquaticlife/testorganism,32%proteinfeedat1%

ofthestockingbiomass/dintwodailyslots(preferablymorningandevening)witha

floating system need to be fed (CostaPierce, 1998). The feeding regime for fish

mentionedin

USEPA

(2002)

can

also

be

adopted.

Aerationandoxygenrequirements:SufficientDO(4.0mg/Lforwarmwaterspecies

and6.0mg/L for coldwaterspecies) shouldbe maintained in the pond for proper

environmentfortestorganisms.TheDOdepletionisnotaproblemincaseofaflow

throughsystembecauseaerationoccursasthewaterpassthroughthesystem.IfDO

decreasestoalevelthatwouldbeasourceofadditionalstress,theturnoverrateof

thewatervolumemustbeincreased(i.e.theHRTofthesystemmustbedecreased)

sufficientlytomaintainacceptableDOlevels(USEPA,2002).Alternativelyfountainor

cascadeaerationarrangementsmaybeprovided.

Requirement of Dechlorination: Dechlorinated effluent only should be passed

through the bioassay pond. If the effluent from the STP is chlorinated, the total

residualchlorineintheeffluentshouldbenondetectableafterdechlorination.

Bioassaytestacceptabilitycriterion:Nomortality (100%survival)of testorganisms

underanycondition.

SalientFeaturesofRecommendedSTPs

Continuousmeasurement

of

flow

at

the

inlet

and

outlet

Excellentpreliminarytreatment

Treatmentuptotertiarylevel

Onlinebioassaytest

Designedandbuiltasmodularunits

PumpingandSTPstobetakentogetherforcontracting/bidding


16/23


16|P a g e

9. ReferencesAPHA, AWWA, WEF (1995) Standard Methods for the Examination of Water and

Wastewater, 19th ed. American Public Health Association, American Water Works

Association,WaterEnvironmentFederation,Washington,DC.

Arceivala,S.

J.

and

Asolekar,

S.

R.

(2006)

Wastewater

Treatment

for

Pollution

Control

(3rd

Edition),McGrawHillEducation(India)Pvt.Ltd.,NewDelhi

Asolekar,S.R.andGopichandran,R. (2005)PreventiveEnvironmentalManagement

An IndianPerspective,FoundationBooksPvt.Ltd.,NewDelhi (the Indianassociateof

CambridgeUniversityPress,UK)

CostaPierce, B.A. (1998) Preliminary investigation of an integrated aquaculture

wetlandecosystemusingtertiarytreatedmunicipalwastewater inLosAngelesCounty,

California.Ecol.Eng.10,341354.

Hoan,V.Q.,Edwards,P. (2005)Wastewaterreusethroughurbanaquaculture inHanoi,

Vietnam:Status

and

prospects,

in:

Costa

Pierce,

B.A.,

Desbonnet,

A.,

Edwards,

P.

(Eds.),

UrbanAquaculture,CABIPublishing,Wallingford,UK,pp.103117.

Kumar,R. (2010) DraftUnpublishedReportentitled: StatusofSewageWastewaterand

TechnologyReviewInIndia,NEERIZonalOffice,Mumbai

Tare,V.andBose,P.(2009)CompendiumofSewageTreatmentTechnologies, National

RiverConservationDirectorate,MinistryofEnvironmentalandForests,Governmentof

India

USEPA (2002) Methods for Measuring the Acute Toxicity of Effluents and Receiving

Waters toFreshwaterandMarineOrganisms. Fifth ed.EPA821R02012. Washington

DC,U.S.A.


17/23


17|P a g e

AppendixI:ExhibitsonOptionsfor

SecondaryTreatment

Exhibit

1:

ASP

Conventional

Activated

Sludge

Process

SchematicDiagram

of

aConventional

Activated

Sludge

Process

Activated Sludge Process (ASP) is a suspended growth aerobic process. It is provided

with primary clarifier to reduce the organic load in biological reactor (aeration basin).

About 40% of organic load is intercepted in primary clarifier in the form of sludge,

decreasing the loading in the aeration tank. Detention period in aeration tank is

maintained between 46 h. After aeration tank, the mixed liquor is sent to secondary

clarificationwheresludgeand liquidareseparated.Amajorportionofthesludgeisre

circulatedandexcesssludgeissenttoadigester.

Sludgegeneratedinprimaryclarifierandexcesssludgefromsecondaryclarifierarenot

matured, digestion of such sludge is essential before disposal. In anaerobic sludge

digestion,suchsludgeproducesbiogaswhichcanbeusedforpowergenerationbygas

engines.Generatedpowercanbeusedforoperationofplant.

Merits

Goodprocessflexibility

Reliableoperation

Proventrackrecordinall plantsizes

Lessland

requirements

Lowodoremission

Energyproduction

Abilitytowithstandnominalchangesinwatercharacteristics

Demerits

Highenergyconsumption

Skilledoperatorsneeded

Uninterruptedpowersupplyisrequired

Requiressludgedigestionanddrying

Lessnutrientremoval

PSTInfluent Effluent

Aeration

TankSecondary

Clarifier

ReturnedSludge ExcessSludge


18/23


18|P a g e

Exhibit2: MBBR MovingBedBiofilmReactor

SchematicDiagramofaMovingBedBioReactor

MovingBedBiofilmReactorisanaerobicattachedbiologicalgrowthprocess.Itdoesnot

requireprimaryclarifierandsludgerecirculation.Rawsewage,afterscreeningandde

gritting,is

fed

to

the

biological

reactor.

In

the

reactor,

floating

plastic

media

is

provided

whichremains insuspension.Biologicalmassisgeneratedonthesurfaceofthemedia.

Attached biological mass consumes organic matter for their metabolism. Excess

biological mass leaves the surface of media and it is settled in clarifier. Usually a

detentiontimeof5to12hisprovidedinthereactors.

MBBR were initially used for small sewage flow rates and because of less space

requirement.In largeplant,mediaquantity isveryhighand itrequires longshutdown

periodforplantmaintenance.Infact,itmaynotbesuccessfulforlargecapacityplants.

Moreovertheplasticmediaispatentedandnotavailableintheopenmarket,leadingto

singlesupplierconditionswhichlimitordenypricecompetition.Inaddition,duetovery

less detention time and other engineering factors, functional Moving Bed Biofilm

ReactorinIndiadonotproduceacceptablequalityeffluent.

Merits

Moving Bed Biofilm Reactor needs less space since there is no primary

clarifieranddetentionperiodinreactorisgenerally45h.

Abilitytowithstandshockloadwithequalizationtankoption

Highoperatoroversightisnotrequired

Demerits

Highoperatingcostduetolargepowerrequirements

Notmuchexperienceavailablewithlargercapacityplants(>1.5MLD)

Skilledoperatorsneeded

Noenergyproduction

EffluentqualitynotuptothemarkinIndia

Muchlessnutrientremoval

Designedcriterianotwellestablished

InfluentMBBRI MBBRII

AirBlower

Secondary

Clarifier

ExcessSludge

Effluent


19/23


19|P a g e

Exhibit3: SBR SequencingBatchReactor

SchematicDiagramofaSequencingBatchReactor(AContinuousProcessInBatch)

It is a fillanddraw batch aerobic suspended growth (Activated Sludge) process

incorporating

all

the

features

of

extended

aeration

plant.

After

screening

and

degritting,

sewage is fed to the batch reactor. Reactor operation takes place in certain sequence in

cyclicorderandineachcycle,followingoperationsareinvolved

AnoxicFillingtank

Aeration

Sedimentation/clarification

Decantation

Sludgewithdrawal

A number of largescale plants exist around the world with several years of continuous

operation.

In

India

also,

there

are

large

scale

plants

operating

efficiently

since

more

than

a

year. Hundreds of fullscale plants operated on Sequencing Batch Reactor Technology are

undersuccessfuloperationinJapan.Somepartsarepatentedandnotavailableintheopen

market,leadingtosinglesupplierconditionswhichlimitordenypricecompetition.

Merits

Excellenteffluentquality

Smallerfootprintbecauseofabsenceofprimary,secondaryclarifiersanddigester

RecenttrackrecordavailableinlargeapplicationsinIndiaalso

Biologicalnutrient(N&P)removal

Highdegreeofcoliformremoval

Lesschlorine

dosing

required

for

post

disinfection

Abilitytowithstandhydraulicandorganicshockloads

Demerits

Comparativelyhighenergyconsumption

Toachievehighefficiency,completeautomationisrequired

Highlyskilledoperatorsneeded

Noenergyproduction

Uninterruptedpowersupplyrequired


20/23


20|P a g e

Exhibit4:UASB+ASP UpflowAnaerobicSludgeBlanketFollowedbyActivatedSludge

Process

SchematicDiagramofanUpflowAnaerobicSludgeBlanketProcessfollowedbyASP

It

is

an

anaerobic

process

in

which

influent

wastewater

is

distributed

at

the

bottom

of

the UASB reactor and travels in an upflow mode through the sludge blanket. Critical

components of UASB design are the influent distribution system, the gasliquidsolid

separator (GLSS) and effluent withdrawal design. Compared to other anaerobic

processes,UASBallowstheuseofhighhydraulicloading.

Merits

Relativelysimpleoperationandmaintenance

Noexternalenergyrequirementandhencelessvulnerabletopowercuts

Noprimarytreatmentrequired

Energyproduction

possible

but

generally

not

achieved

Lowsludgeproduction

Nospecialcareorseedingrequiredafterinterruptedoperations

Canabsorbhydraulicandorganicshockloading

Demerits

Posttreatmentrequiredtomeettheeffluentstandard

Anoxiceffluentexertshighoxygendemand

LargeLandrequirement

MoremanpowerrequireforO&M

Effluent quality is not up to the mark and poor fecal and total coliform

removal

FoulsmellandcorrosionproblemsaroundSTParea

Highchlorinedosingrequiredfordisinfection.

Lessnutrientremoval

EffluentAeratio

nTank

ReturnedSludge

Secondary

Clarifier

UASBInfluent

Sludge

Gas

ExcessSludge


21/23


21|P a g e

Exhibit5: MBR MembraneBioreactor

SchematicDiagramofaMembraneBioreactor

It

is

a

biological

reactor

with

a

suspended

biomass.

The

solid

liquid

separation

in

membranebioreactorisachievedbyamicrofiltrationmembranewithporesizesranging

from0.1to0.4m.Nosecondaryclarifierisusedandhastheabilitytooperateathigh

MLSS concentrations. Membranes are patented and not available in the open market,

leadingtosinglesupplierconditionswhichlimitordenypricecompetition.

Merits

Lowhydraulicretentiontimeandhencelowfootprint(area)requirement

Lesssludgeproduction

Highqualityeffluentintermsoflowturbidity,TSS,BODandbacteria

Stabilizedsludge

Abilitytoabsorbshockloads

Demerits

Highconstructioncost

Veryhighoperationcost

Periodiccleaningandreplacementofmembranes

Highmembranecost

Highautomation

Foulingofmembrane

No

energy

production

Influent

Effluent

Anoxic

Zone

MixedLiquid

recirculationpump

BIOREACTOR

Aeration AirScourBlower

PermeateWasteSludge

MixedLiquid

Recycle

Membrane

Module


22/23


22|P a g e

Exhibit 6: WSP Waste Stabilization Pond (Combination of Anaerobic

andAerobicPond)

SchematicDiagramofaWasteStabilizationPond

Sewage istreated inaseriesofearthenponds. Initiallyafterscreeninganddegritting it is

fedtoananaerobicpondforinitialpretreatment;depthofanaerobicpondisusually3to3.5

m;asaresultthelowersectionofponddoesnotgetoxygenandananaerobicconditionis

developed.BODreductiontakesplacebyanaerobicmetabolismandgaseslikeammoniaand

hydrogensulphideareproducedcreatingodorproblems.AfterreductionofBODby40% it

enters the facultative/aerobic pond, which is normally 1 1.5 m in depth. Lesser depth

allows continuous oxygen diffusion from atmosphere; in addition algae in the pond also

producesoxygen.

ThoughBODattheoutletremainswithintherange,sometimestheeffluenthasgreencolor

duetopresenceofalgae. Thealgaegrowthcancontributetothedeteriorationofeffluent

quality (higher total suspended solids) from time to time. Moreover, coliforms removal is

also

in

1

2

log

order.

The

operating

cost

of

a

waste

stabilization

pond

is

minimum,

mostly

related to the cost of cleaning thepond once in two to three years. A waste stabilization

pond requires a very large land area and it is normally used for small capacity plant,

especiallywherebarrenlandisavailable.

Merits

Simpletoconstructandoperateandmaintain

Lowoperatingandmaintenancecost

Selfsufficiency,ecologicalbalance,andeconomicviabilityisgreater

Possiblerecoveryofthecompleteresources

Goodabilitytowithstandhydraulicandorganicloadfluctuations

Demerits

Requiresextremelylargeareas

Largeevaporationlossofwater

Iflinerisbreached,groundwaterisimpacted

Effluentqualitymayvarywithseasons

Noenergyproduction

Comparativelyinferiorqualityofeffluent

Lessnutrientremoval

Highchlorinedosingfordisinfection

Odorandvectornuisance

Lossofvaluablegreenhousegasestotheatmosphere

Anaerobicpond

HRT=1day

Facultativepond

HRT=5days

Maturationponds

HRT=34daysInfluent

Sludgestoragelagoon

and

Sludgedryingbeds

Aquaculturepond

(HRT > 12days)

(optional)

Effluent


23/23


23 | P

Exhibit7: CW ConstructedWetlands

Wetlands are natural processes similar to stabilization ponds. Wetlands are shallow

ponds comprising of submerged plants and floating islands of marshy species. Natural

forces including chemical, physical, biological and solar is involved in the process to

achieve wastewater treatment. Thick mats of vegetation trap suspend solids and

biologicalprocesstakesplaceattherootsoftheplants.Itproducesthedesiredquality

oftreatedsewagebutlandrequirementisveryhigh,thoughitislesscomparedtowaste

stabilizationpond.Runningcostiscomparativelylow.

Wetlandprocesshavenotyetestablishedcomparedtootherprocesses.Therearetwo

typesofsystems;surfaceandsubsurfacedistributionofsewage.Thetypeofvegetation

grown varies, in some cases there is regular tree cutting and plantation as a part of

maintenancework.PlantslikeTypha,Phragamites,KattailcanbeusedinIndia.Another

typeof

wetlands

use

aplant

called

duckweed

for

treatment.

This

weed

has

avery

fast

metabolicrateandabsorbspollutantsveryquickly.

Merits

Simpletoconstructandoperateandmaintain

Lowoperatingandmaintenancecost

Selfsufficiency,ecologicalbalance,andeconomicviabilityisgreater

Possibilityofcompleteresourcerecovery

Goodabilitytowithstandhydraulicandorganicloadfluctuations

Demerits

Requireslargearea

Largeevaporationlossofwater

Noteasytorecoverfrommassiveupset

Iflinerisbreached,groundwaterisimpacted

Effluentqualitymayvarywithseasons

Noenergyproduction

Nonutrientremoval

Odorandvectornuisance

Lossofvaluablegreenhousegasestotheatmosphere

STP_NRCD_Guidelines

Documents

Transcript of STP_NRCD_Guidelines