Chulli Water Purifier Professor M. Fakhrul Islam Dept. of Applied Chemistry & Chemical Technology , Rajshahi University Bangladesh Back Drop Arsenic contaminated Tube wells Total No Tube wells Contaminated --- Almpst 25% of the Number Installed Population affected 30 million , one third of the population almost lower half of the country

Back Information Arsenic contaminated tube wells : Almost 25% of the total installed. Almost lower half of the country arsenic affected. No. of people at risk : 30 million or more. People have already developed arsenicosis symptoms drinking the arsenic tainted water

Suggested Mitigation Options Surface water use. Rain water storage in concrete tanks. Pond , river water and large water bodies : use of sand filtration. Dug well. These are all in effect rainwater use , but may be variously contaminated by suspended particles dissolved impurities and bacteria B. Deep aquifer water use : Deep tube well based piped water system Arsenic filters Each has its merits and demerits from different considerations discussed as pointed out by many. Not used widely .

Other Possible Systems Bacteria filters for surface water. Thermal treatment of surface water after filtration. Sunlight and UV radiation treatment of surface water. Chemical treatment of surface water (chlorination etc) These are physico –chemical and chemical processes, excepting the thermal treatment i.e boiling of water, none are practiced in villages for different reasons Boiling Surface water produce very safe bacteria free water but high cost due to high fuel cost

Cooking - Energy Sources in Bangladesh Village : wood and dried plant materials & cow dung. Small towns: Mostly wood but some gas. Big towns: Cities in Eastern part gas; but in Western part no gas, use bottled gas or wood. Gas reserve: To last for another 5-6 years only if no big reserve discovered now. Coal: may be used in future in towns and villages Energy position is bleak and may be same in villages and even for towns in the future. Cost increase and availability to decrease with time . Boiling of extra water for producing safe drinking water will decrease forest area and also gas reserve very fast.

THE CHULLI CONCEPT Bangladesh mud chulli used every where Chulli wastes enormous heat energy (>80% ,BCSIR) Villagers cook 2-3 times daily Waste heat use will save much energy and ultimately environment . Chulli temperature high inside Alternative to Boiling Water passed through a small dia. coiled pipe inside chulli heated to 70* or more very quickly, Bacteria killed very fast

Suggested Mechanism of pasteurization by heat treatment in coiled pipe Very high turbulence due to heat and flow. Many repeated contact of bacteria with hot surface (Brownian movement and turbulence). Rapid heat transfer for large surface area compared to boiling in pot. The following slides show the principal aspects of chulli water purifier

Chulli Water Purifier Diagrammatic

A Practical Chulli Water Purifier

Water Flow in Hot Pipe

Chulli Water Purifier Data Coil size Chulli dimension Operation time Temperature of water collection Amount of water produced average 10” dia Pipe 4 turns 1- 1/2 feet Deep, 10” dia. Rice cooking time approximately 40 minutes 70- 76*C 30 Liters+ Total coliform counts in treated water counts/100ml Experiment No Initial counts in Pond water Counts after pass through chulli 1 1750 2 2500 3 560000 Tota

Bacteria Test Data Total coliform counts /100 ml in water   Run Initial in Pond water after pass through chulla 1 1750 0 2 2500 0 3 560000 0 N.B Analysis for other chemical water parameters not done, but assumed to be within safe limits as generally found.

Field Test Till now almost 3000 chulli water purifier units installed in >11 upozillas of different districts affected with arsenic in tube wells with assistance from UNICEF by a local NGO . Field test data match the experimental chulli purifier data . Very highly bacteria contaminated water can be treated. Almost all types of water from pond ,river and baor can be made bacteria free. Clean water obtained. Social acceptability varies place to place

Conclusion Water pasteurization at no extra fuel cost. Extremely easy to set and operate. Large amount of bacteria free safe water produced by a single chulli for 2-3 families. Very low cost (Tk 450 for the whole unit). All components locally available. Principle applicable to other large waste heat generators such as rice mills ,brick kilns after thorough technical research for volume production of water from surface waters in the arsenic affected and non affected areas.

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