Le traitement de l'eau
Household Water Purification: Low-Cost Interventions
Col VK Agrawal (Retd)*, Brig R Bhalwar+
Numerous studies have shown that improving the microbiological quality of household water by point-of-use treatment reduces diarrhoea and other waterborne diseases. The most promising and accessible of the technologies for household water treatment are filtration with ceramic filters, chlorination with storage in an improvised vessel, solar disinfection in clear bottles by the combined action of UV radiation and heat, thermal disinfection (pasteurization) in opaque vessels with sunlight from solar cookers or reflectors and combination systems employing chemical coagulation-flocculation, sedimentation, filtration and chlorination. However each of these technologies have limitations and effectiveness can be increased by use of two or more treatment systems in succession for improved treatment and the creation of multiple barriers. In particular those treatments that provide no residual disinfectant, such as boiling, solar treatment, UV disinfection with lamps and filtration could be followed by chlorination to provide a multibarrier approach. Water purifiers based on multiple interventions such as filtration/ultra filtration/ activated carbon adsorption / UV rays disinfection are available in the market which can be used to purify the water at point of use. Water purifiers based on single interventions like candle filters, resins filters or ultraviolet lamp can be used in most places being supplied water after purification. Troops on operational move can purify water by fabric/resins filtration and chlorine disinfection or by flocculent-disinfectant.