Reverse osmosis: Indiatcdc2.undp.org/GSSDAcademy/SIE/Docs/Vol11/SIE.v11_CH5.pdf · Reverse osmosis:...

Reverse osmosis:India

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GENERAL INFORMATION

❖ Implementing institution:Central Salt and Marine Chemicals Research Institute(CSMCRI)

❖ Head:Dr. Pushpito Kumar Ghosh (director)

❖ Details of institution:Address: Central Salt and Marine Chemicals ResearchInstitute, Gijubai Badheka Marg, Bhavnagar-364 002,Gujarat, India

Tel.: (+91) 278 256 7760 / 9496

Fax: (+91) 278 256 7562

E-mail: [email protected], [email protected]

Web site: www.csmcri.org

❖ Implementation period:Each part of the project (two-stage seawater reverseosmosis and animal-powered reverse osmosis) took two years to implement.

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62 V O LU M E 11: S A F E D R I N K I N G WAT E R

S U M M A R Y

Many villages in India, particularly incoastal areas, do not have an adequatedrinking water supply and whateverwater is available locally tends to bebrackish. In such areas, the Central Saltand Marine Chemicals Research Institute(CSMCRI) has installed a number ofwater purification plants designed byInstitute staff and incorporating a thinfilm composite (TFC) reverse osmosis(RO) membrane developed by Institutescientists. Important lessons learned during the installation of such units were:

• obtaining a reliable electricity supply is always problematical;

• villagers do not like the idea ofchemicals being added to water,even though such chemicals areremoved before the water is safefor drinking;

• precise compliance with interna-tional water quality standards isless of an issue than providingwater of reasonable quality in

adequate quantities and at a cost that government agenciesentrusted with the job of supplying water can afford;

• water treatment units should be of a size appropriate for cateringonly to villages in their immediateproximity; otherwise, transportingthe water becomes a problem;

• water treatment units must berobust and easy to operate so thatlocal personnel can be trained intheir operation;

• there is an ongoing need forappropriate solutions in the after-math of natural disasters such asearthquakes, floods and tsunamiswhen the provision of drinkingwater becomes an urgent issue.

Recognizing these issues, CSMCRI has:

• improved the flux of its RO membrane without compromisingits salt rejection efficiency;

• developed simple RO systems thatavoid the use of chemicals;

❖ Costs:Two-stage seawater reverse osmosis phase: US$300,000,including US$100,000 for capital costs (salaries and infrastruc-ture) at the Council for Scientific and Industrial Research (CSIR),allocated to the Department of Science and Technology (DST),New Delhi, and US$70,000 allocated to the District CollectorateRamanathpuram, Tamil Nadu State, to cover civil work and 25per cent of equipment costs.

Animal-powered reverse osmosis phase: US$30,000, includingUS$22,000 for salaries, infrastructure and a rural action programme at CSIR, New Delhi, and US$8,000 supplied by M/sPepsico India Holdings Ltd., Gurgaon, allocated for capital costs.

Reverse osmosis: India 63

• used its high-flux membrane modules to develop a two-stageRO desalination unit capable ofproducing 500 to 1,000 litres ofsafe drinking water per hour atlow pressure (600 pounds persquare inch, psi) (and therefore at a lower cost and with improvedsafety) from seawater or highlybrackish groundwater desalination;and

• developed a speed increaser, oraccelerator, that allows the ROunit to be interfaced with powersupplied by oxen to convert brack-ish water into potable water at arate of 500 to 800 litres per hour.

CSMCRI has successfully demon-strated the effective functioning of prototype RO units in villages. TheInstitute is now further fine-tuning thetechnology and attempting to reducecosts while implementing the large-scaleuse of RO systems that go beyonddemonstration projects.

B A C K R O U N D A N D

J U S T I F A C T I O N

Osmosis is the process by which waterpasses through a semipermeable mem-brane from a dilute solution to a more con-centrated solution without any input ofenergy. Reverse osmosis (RO), however,involves high pressures to force pure (ornearly pure) water through a semiperme-able membrane, leaving behind any dis-solved chemicals in the original solution.

Among the problems associated withthe widespread uptake of the reverseosmosis of brackish water is the fact thatit is unsuitable if the water to be desali-nated contains too much salt. This meansthat seawater cannot be used as a sourceof drinking water. In addition, electricityis needed to provide the power to driveRO systems, but areas that lack safedrinking water often also lack a reliablesource of electrical power. Some smallsystems designed to treat water that isnot too brackish can be run using solar orwind power, but both sources of energyare costly and weather-dependent. Incontrast, animal power is often readilyavailable in many rural areas. Even so,until now, animals had not been used todrive an RO desalination plant.

The State of Tamil Nadu in southeastIndia, particularly the district ofRamanathpuram, faces an acute shortageof drinking water. Since it is a coastalarea, however, seawater and highlybrackish underground water are plentiful.Large seawater RO desalination plantshave been installed in the district butreplacement membrane modules areexpensive and maintenance costs arehigh. Large, centrally managed plantsalso add to the cost of transporting waterto end-users. Smaller plants located inindividual villages or catering to a clusterof villages are an attractive option butsuitable low-capacity seawater desalina-tion plants are too expensive.

CSMCRI scientists are responding tothese challenges, aiming to develop andadapt indigenous technologies for water


desalination that will suit both the require-ments of government water supply agen-cies and the needs of rural communities.

To desalinate seawater, semiperme-able membranes must have a 99-per centsalt rejection capability and are typicallyoperated at pressures greater than 800psi. This is technologically difficult, soCSMCRI scientists developed an alterna-tive, novel method based on a two-stagedesalination process using a high-fluxthin film composite (TFC) RO mem-brane developed in-house for use withbrackish water.

The advantages of this methodincluded:

• the possibility of desalinating seawater at a pressure of 600 psi,allowing the use of less expensivehardware and thereby reducingcapital costs; and

• the high flux of the brackish watermembranes meant that operatingcosts became comparable withthose of sophisticated seawaterdesalination units.

CSMCRI proposed the use of its two-stage seawater desalination technologyto local officials in Ramanathpuram dis-trict and offered to install two prototypeunits capable of desalinating 2,000 litresof water per day. It was agreed that thetwo units should be installed in villagesthat were the most hard-pressed. In addi-tion, the Ramanathpuram Administrator(Collector) offered to build the necessaryinfrastructure and contribute US$10,000for the units besides civil costs, the

balance of the costs being secured byCSMCRI. Realizing that once a unitbegan operating, its value would be recognized, CSMCRI decided to procurethe balance of the funds from its internalresources before approaching entitiessuch as the Department of Science andTechnology for further funds.

The justification for developing ananimal-powered RO unit was that theelectricity supply in villages, especiallythe three-phase power required for medi-um- to large-capacity RO desalinationunits, was usually lacking. In contrast,during the summer months when therequirement for drinking water is espe-cially acute, draught animals, common inmany villages, had less work. In addition,following natural disasters such as thesupercyclone that hit Orissa in October1999, the earthquake that hit Kutch inJanuary 2001 and the Asian tsunami ofDecember 2004, a lack of electricalpower means that alternative energysources must be used to relieve the imme-diate crisis concerning the availability ofsafe drinking water.

In all these cases, animal power couldhave been put to use. In more day-to-daysituations, there are many isolated com-munities that are not connected to thenational power grid. In addition, thereare cases where generators are notacceptable and “silent” power is required,for example in the Sundarbans TigerReserve in West Bengal. CSMCRI, there-fore, developed a speed increaser thatallows its high-flux RO unit to be inter-faced with power supplied by oxen.


These animal-powered systems are capable of converting brackish water intopotable water at a rate of 500 to 800 litresper hour.

D E S C R I P T I O N

CSMCRI has been engaged in theresearch and development of membranesfor the past 30 years and has installed anumber of RO plants throughout India.Initially, these were based on a celluloseacetate membrane. In the early 1990s, theInstitute developed a thin film composite(TFC) RO membrane but the flux, or therate at which it allowed water to flowthrough it, was not considered highenough for practical situations. TheInstitute therefore intensified its researchin this area and produced a TFC mem-brane with an increased salt rejection effi-ciency of around 95 per cent and anincreased permeation rate of 60 to 68 litresper square metre per hour under standardtest conditions. This made the membranesideal for brackish water applications andbrought down the capital cost of desalina-tion plants by almost 50 per cent.

SI N G L E-S T E P S Y S T E M S

The first plant, which was established inthe village of Mocha in Gujarat, westernIndia, in January 2000, uses a single-stepprocess to desalinate brackish groundwa-ter. The plant, which has operated con-tinuously since then, has an output of1,800 litres per hour and caters to theneeds of 2,000 villagers (fig. 1). Suchplants, based on the latest technology,cost around US$12,000 to install andproduce water at an estimated cost ofUS$0.90 per thousand litres.

As the data from another plantinstalled in Kisari village, also inRajasthan, show (table 1), using the sin-gle-step RO process results in a dramaticimprovement in quality between thebrackish input water and the outputwater or permeate. Not only was there alarge reduction in total dissolved solids(TDS), but water hardness, fluoride andnitrate levels were also brought withinsafe limits. In addition, the local school-teacher reports that many ailments previ-ously suffered by children have been vir-tually eliminated.

Figure 1. The thin film composite

reverse osmosis plant installed at Mocha,

Gujarat, capable of producing 1,800 litres

of safe drinking water per hour.


A novel feature of these two plants inGujarat and Rajasthan is that no chemi-cals are added to the water.

TW O-S TA G E S Y S T E M S

A two-stage TFC RO process has alsobeen successfully developed and used totreat seawater. Normally, seawater, whichhas a salinity of between 30,000 and35,000 parts per million (ppm) of totaldissolved solids (TDS), is desalinated atpressures greater than 800 psi using mem-branes with very high (more than 99 percent) salt rejection efficiency. Since themembranes developed by CSMCRI arelimited in this regard (they have a saltrejection efficiency of around 95 per

cent) but have the advantage of having ahigh flux, the possibility of carrying outlow-pressure (less than 600 psi), two-stage seawater desalination was explored.In the first stage, the aim was to reducethe salinity to between 5,000 and 6,000ppm. Thereafter, in the second stage, thispermeate would be further desalinated toachieve a salinity of less than 1,000 ppm.

The first prototype unit was installedin Nelmadur village (about 30 km fromParamakudi) in Ramanathpuram district,Tamil Nadu. It cost about US$12,000 tobuild and has been operational sinceApril 2004 (fig. 2). Table 2 providesdetails of the raw water and productwater. The plant operates for seven hoursa day, using some 7,500 litres of seawater

Table 1. Water quality before and after treatment in a single-step reverseosmosis unit in Kisari village, Rajasthan.

PARAMETER INPUT WATER (PPM)* OUTPUT WATER (PPM)

Total dissolved 1,907 148solids (TDS)

Fluoride 1.74 0.17

Hardness (as CaCO3) 261 9

Nitra 151 23

* ppm = parts per million (equivalent to milligrammes per litre).

Figure 2. The two-stage seawater

desalination unit in operation at Nelmadur,

Ramanathpuram District, Tamil Nadu.

(“Meetha Sagar” means “sweetened sea”.)


to produce 3,000 litres of water suitablefor human consumption, a 40 per centrecovery rate. This meets the require-ments of some 1,500 to 2,000 local peo-ple. However, there are plans to increasethe output of the unit by increasing thenumber of hours during which it operatesin order to satisfy a growing demand.Two-stage RO plants with a capacity of1,000 litres per hour would cost aroundUS$22,000 to install and would producewater at an estimated cost of US$2.20 perthousand litres.

AN I M A L-P O W E R E D S Y S T E M S

The problem with using oxen to power aRO unit is that the input power has a lowspeed (about two revolutions per minute,rpm) and high torque (the oxen are con-nected to the machinery via a 4-metreshaft) whereas the output requires a highspeed and low torque. This conversionhas been achieved by designing a speedincreaser, which is coupled to the inputshaft. The speed increaser comprisesthree sets of helical bevel gears to producean output of some 200 rpm. This output is

fed, via a crankshaft, to a high-pressurepump that discharges 20 litres per minuteof feed or input water under a pressure of200 to 300 psi, depending on thephysique of the animals. This hydraulicpressure is adequate to carry out desalina-tion of feed water with up to 5,000 ppmof TDS using any RO membrane elementdesigned for brackish water, but theInstitute uses its indigenously developedTFC RO membrane elements.

Two problems discovered when aprototype unit was tested at CSMCRI inBhavnagar were that there were an insufficient number of RO modules,which resulted in a low rate of recovery,and there were additional losses in theform of frictional energy caused by awooden roller attached to the mechanicallink, which, in turn, increased the loadon the animals.

These problems were overcome byincreasing the number of RO modulesand by replacing the wooden roller witha wheel and tyre assembly (fig. 3).Additional studies showed that oxen haveno difficulty in working up to six hours a

Table 2. Water quality before and after treatment in a two-stage reverseosmosis unit in Nelmadur, Tamil Nadu. In this case, the input water was seawater.

PARAMETER INPUT WATER (PP)* OUTPUT WATER (PPM)

Total dissolved 36,540 1,060solids (TDS)

Fluoride 1.0 0.2

Hardness (as CaCO3) 1,500 20

Nitra 8 0

pH 7.5 6.7

* ppm = parts per million (equivalent to milligrammes per litre).


day provided that they are given occa-sional rest periods. Using this systemwith input water containing 5,000 ppmTDS, the peak performance measuredwas 780 litres of drinking water producedper hour with a 65-per cent recovery rate,while the average performance was 600litres produced per hour with a 50-percent recovery rate. Animal-poweredplants cost around US$5,000 to installand produce water at an estimated cost ofUS$1.20 per thousand litres, includingthe cost of feeding the animals and oper-ator expenses.

At the request of the Public HealthEngineering Department of West Bengal,an animal-powered RO unit was set up inFebruary 2004 on Mach Ranga DeepIsland in Hasnabad, North 24 ParganasDistrict, to treat saline pond water with4,200 ppm TDS. The unit cost aboutUS$6,000 to build. Also, in view of theability of RO to eliminate all kinds ofharmful elements, it was agreed thatwater from neighbouring areas, whichsuffers from high TDS as well as naturalcontamination with arsenic, would be

treated. The Public Health EngineeringOffice has since written to CSMCRI confirming that the unit has reduced theturbidity, salinity, iron and arsenic con-tent of the water, making it safe to drink,adding that public health engineersappreciate plants that are able to elimi-nate two to three undesirable compo-nents simultaneously.

In addition, as with the single-stepand two-stage units, no chemical addi-tives are required to produce potablewater, a unique property of the CSMCRIRO desalination units. Also, although theprototype unit was powered using oxen,it is relatively simple to adapt the unit toother draught animals such as camels.

P AT E N T I N G A N D

C O M M E R C I A L I Z AT I O N

Four patents have either been granted orare undergoing review:

Design and development of a mem-brane casting machine, Indian Patent No.145945;

Figure 3. A reverse osmosis unit

for the desalination of groundwater

powered by oxen. Inset shows the

wheel and tyre arrangement used to

decrease friction and increase the

mechanical efficiency of the unit.


A process for the preparation of highflux-high separation thin film compositereverse osmosis membranes for desalina-tion of highly saline waters, Indian PatentNo. 169550;

Animal powered mechanical devicefor water desalination. N. Pathak, P.K.Ghosh, S.L. Daga, V.J. Shah and S.N.Patel. Patent application no. PCT/IB02/056060; and

Polyamide composite membrane forreverse osmosis and method of prepara-tion of the same, Indian patent applica-tion no. 1216/DEL/2004, 30 June 2004.

P A R T N E R S H I P S

Among the partners for the conventionalone-step and the two-stage desalinationprojects were:

• the Department of Science and Technology, Ministry ofScience and Technology of theGovernment of India, New Delhi,which provided financial support;

• the District Collectorate,Ramanathpuram District, TamilNadu, which collaborated to setup the first two-stage unit; and

• Chennai Petrochemicals Limited and the Centre for High Technology, New Delhi,India, which helped to set up a demonstration plant to promoteindigenous technology for recycling water.

Among the partners for the animal-powered desalination projects were:

• Pepsico India Holdings Ltd.,which desired to install a unit in a disaster-prone area;

• Rajasthan Mines and Minerals,which was interested in develop-ing a camel-powered unit;

• Rural Action Plan, CSIR, New Delhi; and

• Hasnabad Gram Panchayat (village council).

In addition, the Global ResearchAlliance is keen to collaborate with CSM-CRI on drinking water and sanitationprojects relating to desalination, defluori-dation and the removal of arsenic.

R E P L I C A B I L I T Y

Providing good-quality drinking water invillages and other remote areas is a glob-al issue and the innovative ways of desalinating brackish groundwater andseawater developed by CSMCRI shouldbe highly relevant to other regions.However, replicability on a large scalewill depend on the ability of the Instituteto license the technologies for bothmembrane manufacture and plant designas the Institute itself can produce theunits only in limited quantities. Indeed, inan article in the New Scientist magazineabout the CSMCRI animal-powered ROunit, a spokesman for the IntermediateTechnology Development Group, UnitedKingdom, was quoted as saying that “the


device holds great promise for the 1.2 bil-lion people around the world who lackclean water and electricity, but who haveplenty of oxen”.

P O L I C Y I M P L I C AT I O N S

Recently, the Government of India hasbegun to look much more favourably ondesalination than it had in the past. Thefavourable reception of the RO units thatCSMCRI has put in place and thehumanitarian nature of the various proj-ects have also put the Institute in a posi-tion where it is better able to influencegovernment policies, with argumentsbased on quantitative data rather thanemotional arguments.

Although the work of the Institutehas not led directly to any changes in leg-islation, it has certainly played a role ininfluencing government policies, at leastin Rajasthan, Tamil Nadu and WestBengal, in favour of indigenous RO technology. There is now a willingnessby local governments to place orderswith CSMCRI rather than importing ROunits. Another issue that needs to be tack-led is the disposal of highly saline rejector waste RO water, particularly in inlandareas. In these cases, practical policyguidelines will be necessary.

L E S S O N S L E A R N E D

Various obstacles were faced during theimplementation of the projects describedin this case study. Among them was cyn-

icism concerning the efficacy of a tech-nology developed in India, given that ROmembranes were traditionally developedby large multinational companies such asthe Dow Chemical Company andDuPont. In addition, there was cynicismabout the relevance of using RO technol-ogy in villages since many plants previ-ously installed by private companies(albeit based on a different type of mem-brane) were lying abandoned. Linked tothis, decision-makers believed that ROplants were expensive and they had littleawareness that not only has the technol-ogy moved forward but the value placedon safe drinking water is also much high-er today. Improved technology nowmakes the costs of establishing RO plantsmore attractive and both village adminis-trators and water board engineers arenow educated as to maintenance andoperation costs.

Among the problems encountered inthe early stages of the project was poorplant maintenance, which led to frequentbreakdowns. This was due to three fac-tors: (a) inadequate training of local oper-ators; (b) the view of Institute staff thatthey should be the ones to undertake thepreventive maintenance treatments eventhough they were not able to visit thesites frequently enough; and (c) villagepolitics, leading to the replacement oftrained personnel with people chosen bylocal politicians and community leaders.Points (a) and (b) have been addressed,but point (c) remains an area of concern.Although there were difficulties in trans-ferring know-how, the viability of theplants being operated by the people and


for the people has now been established.Even so, Institute staff are responsible foroperating the plants for the first twoyears so that their performance is moni-tored and local people can see for them-selves how well the plants are running.

In the beginning, however, local people distrusted the water quality anddid not accept the use of chemical additives even though they were addedto the input water to prolong the life ofthe membrane and did not enter the out-put water. This problem was overcomeby placing a greater emphasis on productacceptability, which was achieved byeliminating the use of chemicals exceptduring routine membrane cleaning oper-ations, even if this meant that the life ofthe membranes was reduced.

Another vital lesson learned is thatwithout financial support from the government, the support of the localadministration and involvement of thevillage council, no project can be success-ful. Fortunately, CSMCRI has been ableto convince the government of the viability of its projects, which has led togenerous funding, while local administra-tions have been highly supportive in providing infrastructure support and partial funding. Logistics concerningoperation timing, the amount of waterrequired and distribution mechanismshave all been worked out in collaborationwith village councils. The receptivenessof these councils to CSMCRI technologyis also partly due to the fact that theInstitute focused on promoting its tech-nologies in those locations where their

competitive advantage would be mostevident. Time was also spent identifyingagencies that believed in the Institute’scapability and showed a determination tocollaborate in the installation of the prototype units. CSMCRI has nowgained considerable experience in villagesituations, including the diversity ofrequirements and what can be consideredas appropriate technology.

I M P A C T

After it had successfully completed twoyears of operation, the Kisari RO plantin Rajasthan was covered on national tel-evision under the title “Sweet Success”. Itwas acclaimed as one of the “greatestsuccess stories of Indian science andtechnology in rural India”. The televisionprogramme also highlighted the healthbenefits (including considerably reducedailments among children, reduced jointpains and the expectation of reduced flu-orosis problems in view of the reducedfluoride content in water) and suchimprovements to the local quality of lifeas tastier and healthier cooking as aresult of the villagers accepting and usingwater produced by the plant. Reports ofthe success of the various CSMCRI proj-ects have also appeared in the foreignmedia and have helped the Institute toachieve greater awareness and earnrespect for its activities. Many govern-ment officials have also visited the plantsand tasted the quality of the water thatthey produce.


Perhaps partly in response to thisfavourable publicity, the Government ofIndia has decided to put a major empha-sis on desalination in coastal areas as wellas regions suffering from problems withbrackish water. Many other agencies alsonow believe that RO is the best optionfor removal of other chemicals that ren-der water unfit for human consumption,including fluoride and arsenic.

A measure of the impact of CSMCRItechnologies is the level of interest thathas been generated by the plants thathave been installed and the number ofrequests for new installations, both largeand small. For example, CSMCRI hasbeen consulted for the installation of aproposed plant producing 0.5 millionlitres per day in Rajasthan for convertingmine water into drinking water; in viewof the success of the Kisari plant, theGovernment of Rajasthan has soughtadditional RO plants for the NagaurDistrict; the Government of West Bengalhas requested that the Institute installthree plants, each with a capacity of5,000 litres per hour; and another requesthas been received from the Tamil NaduWater Supply and Drainage Board toinstall five plants of different capacities(0.1 to 0.5 million litres per day) for thetreatment of saline to highly saline water.The District Administrator ofRamanathpuram, where one of the proto-type units was installed, has also placedorders for more units. More recently, theIndian Army stationed at Car Nicobarhas requested an RO unit after witnessingthe success of a similar plant installed at

the air force base there following theAsian tsunami of December 2004.

However, a model needs to be devel-oped for financing such units and also fortheir sustainable operation, especiallywhere clients are operating under severefinancial constraints. It may be feasiblefor governments to subsidize the installa-tion of such units, with the balance offunds being supplied by donor agenciesor bank loans. Thereafter, a nominalcharge could be levied for the water (sayUS$1 per family per month), whichwould be used to repay loans and tocover routine operation and maintenancecosts. Villagers in Tamil Nadu, for example, are receptive to a charge forwater to cover operational and mainte-nance expenses. There are also opportu-nities for villagers owning oxen to makemoney by providing their animals topower RO units.

The direct impact on local people ofinstalling RO technology can be highlighted using the village ofNelmadur, Tamil Nadu. There, theunderground water is highly brackish andhas a salinity bordering on that of seawater. Originally, villagers had tofetch water from another village locatedthree kilometres away. Today, however,some 290 families (2,000 people) arebenefiting from a plant that was installedin April 2004.


F U T U R E P L A N S

TW O-S TA G E S Y S T E M

In view of the encouraging performance ofthe prototype plant, the Tamil Nadu WaterSupply and Drainage Board has askedCSMCRI to explore the feasibility ofinstalling five additional plants with capac-ities ranging between 0.1 and 0.5 millionlitres per day. The Department of Scienceand Technology has expressed interest inpartnering with CSMCRI in heavily pro-moting desalination, which is now a prior-ity area for the Government with a project-ed budget outlay of US$0.7 million overthree years. CSIR, meanwhile, has sanc-tioned funds for three RO units to replaceunits donated after the Asian tsunami andalso for an additional eight units to be usedfor disaster management.

In addition, as part of a project spon-sored by the Department of Science andTechnology, CSMCRI is aiming toimprove the design of the two-stage seawater RO unit by synchronizing thefirst- and second-stage operations so thatboth proceed simultaneously. This wouldspeed up the process, help to maximizeoutput and reduce capital and operatingcosts by 25 per cent. There are also plansto introduce a nanofiltration step to pre-treat water entering the RO units. Thiswould reduce the TDS, and therefore theosmotic pressure, thus reducing the ener-gy required to operate the units, andlower the hardness of the water, whichwould reduce the formation of scaledeposits on the RO membrane.

AN I M A L-P O W E R E D S Y S T E M S

A plan is being developed for the widerimplementation of ox-powered RO unitsin the Sundarbans Tiger Reserve area.

In collaboration with Rajasthan Minesand Minerals, the ox-powered system willbe adapted to run on camel power, which ismore readily available in the arid Rajasthanregion. There are also plans to adapt thespeed increaser so that the animal-poweredunit can be used to desalinate seawater andincrease output. Already, 80 to 100 litres ofpotable water can be produced per hourfrom seawater but this figure needs to beincreased if the technology is to be madepractical. Improving the efficiency of thespeed increaser will also reduce the load onthe draught animals.

Efforts are also under way to developthe commercial cultivation of halophytic(salt-loving) plants using the reject waterfrom RO plants, thereby turning a wasteproduct into something of potential value.

Today, many government and privateinstitutions and organizations are showinggreat interest in collaborating with CSMCRIin promoting its novel RO technologies forthe benefit of rural communities. There areplans to enter into specific licensing agree-ments for manufacturing the membranes andother equipment and marketing the technol-ogy. Non-governmental organizations arebeing approached to help to identify oppor-tunities for the grass-roots implementation,operation and maintenance of CSMCRItechnologies. Discussions are also being heldwith the Global Research Alliance, of whichCSIR is a part, to help to disseminate thesetechnologies globally.


P U B L I C AT I O N S

Prakash Rao, A., Joshi, S.V., Trivedi, J.J.,Devmurari, C.V. and Shah, V.J. (2003).Structure-performance correlation ofpolyamide thin film composite membranes:effect of coating conditions on film forma-tion, Journal of Membrane Science, 211:13-24.

Shah, V.J., Devmurari, C.V., Joshi, S.V., Trivedi, J.J., Prakash Rao, A. andGhosh, P.K. (2004). A case study of long-term RO plant operation without chemicalpre-treatment. Desalination, 161:137-144.

_____. (2004). CSMCRI experience withreverse osmosis and desalination: casestudies. Desalination, 165:202-208.

The development of animal-powered ROdesalination has been featured in severalrecent articles, including:

All hooves to India’s pump, New Scientist,10 May 2003.

Oxen power desalinates water, AppropriateTechnology, vol. 30, No. 3, September 2003.

Bullock power for pure water, NewAgriculturist, July 2003 (www.new-agri.co.uk/03-4/newsbr.html).

Our Planet (United Nations EnvironmentProgramme) Q1, 2004, Books andProducts Section.

Oxen power, Down To Earth, 15 July 2003(Centre for Science and EnvironmentPublication, New Delhi).

Prepared by

Pushpito Kumar GhoshDirector, Central Salt and MarineChemicals Research Institute, GijubaiBadheka Marg, Bhavnagar-364 002,Gujarat, India

Tel.: (+91) 278 256 9496Fax: (+91) 278 256 7562E-mail: [email protected]

Project participants:

P.K. Ghosh: Conception of the two-stage low-pressure seawater and animal-powered desalination units; interactionwith Hasnabad and Ramanathpuramadministrative authorities and fundingagencies; project monitoring.

V.J. Shah, former discipline coordinatorand project engineer: Plant design; proj-ect implementation and monitoring; liai-son with clients and funding agencies.

S.V. Joshi, discipline coordinator:Optimization of TFC membrane andmembrane scale-up.

N. Pathak: Design, development, fabrication and monitoring of animal ROunit; implementation of the project inHasnabad village.

J.J. Trivedi: Membrane preparation and evaluation; feed and product wateranalyses; concept validation of two-stagelow-pressure seawater RO; evaluation ofchemical treatment options.

C.V. Devmurari: Laboratory evaluations;assistance with plant installation and moni-toring of plant performance in the field.

A. Prakash Rao: Monitoring two-stageseawater plant performance; implementa-tion of the chemical treatment of themodules; data recording.

A. Patel: Plant installation; troubleshooting.

K. Eswaran: Logistic support inRamanathpuram; assisted in sanctioningof project.

S. L. Daga: Contributed to initial stagesof animal RO project.

In addition, many other technical staff assist-ed in the implementation of the projects.

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