Question and Answer

Question & Answer Corner

Q1. Nematoda from tap water !?
Q2. Arsenic pollution in the water supply using surface water?
Q3. What kind of advantage can we have, when we change the coagulant from aluminum sulfate to PACl?
Q4. How do algae present in sedimentation tank and influence to water treatment process? (under the translation to English)
Q5. How do you control weed in raw water canal ? (under the preparation)
Q8. For supplying safe water, please show me an example to keep cleanness at pipe construction site .
Q9. Could you advise me on applicability of chlorine dioxide for disinfection?
Q10. Row Water contains high concentration lime. Can lime removed by Bio-filtration method?
Q11. 1. Control of weed in raw water channel.
    2. Chemical use for removing of Duck lettuce (Ottelia alismoides).
Q12. Please compare Cl2 gas with NaClO as a disinfectant (characteristic, easiness of O&M, cost). How many grams of commercial NaClO correspond to the Cl2 gas 1g?
Q12-2. Please compare the commercial NaClO with produced one by the house generation system of electrolysis method. And how many Watt of electric power are necessary for producing 1g NaClO ?
Q13. Small black particles came out from tap in some supplied areas. Why did quality of tap water change? I am researching the reason. Could you help us?
Q14. I would like to make standard operating procedure (SOP) of countermeasure against algae obstacles. Would you introduce case example?
Q15. Recently a pump has strange noise. Tell me what possibly cause the sound and how we can deal with them. (T.M. Vietnam)
Q16. Influence of eutrophication to water supply system and its countermeasures(Ms. N.S. Thailand)
Q17. I am an official who is in charge of water supply in rural. I want to know about Jar-test(Mr. T.H., Laos.)
Q18. Is EM (Effective Microorganisms) effective in order to reduce the water pollution of the river ? (Ms. L.K. Thailand)
Q19. I heard that “Block Distribution System” is effective for measures of leakage reduction and water pressure control. I would like to know the block distribution system. (Mr. R.T. India)
Q20. What kind of condition reduces the effectiveness of PAC in the coagulation process? (Mr. K.A. Japan)
Q21. Arsenic concentration in the well is 0.013mg/L while water quality standard value is 0.01mg/L. The concentration value can be 0.01mg/L by rounding. Then it can ensure the standard. Is such way right?
Q22: Comparing to powder PAC, I want to know the specification, life time, storage and advantage and disadvantage of liquid PAC.
Q23: NRW ratio is 50% around in our water supply.  I want to know a method of NRW reduction. (S.K., Bangladesh)
Q24: Head loss of our rapid sand filters has increased in a short time and the filters have clogged soon. We have often lost filter media from the filters. Let me know the issues to be considered when we select filter media and its maintenance. (Mr. Z.O. Myanmar)

We are waiting answers for following questions