1. 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 million , one third of the population
almost lower half of the country

2. 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

3. 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 .

4. 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

5. 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.

6. 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

7. 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

8. Chulli Water Purifier Diagrammatic

9. A Practical Chulli Water Purifier

10. Water Flow in Hot Pipe

11. 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

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

13. 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

14. 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.

15. THANK YOU