Development and evaluation of filter for canal water potability

Low-cost portable water filter having a capacity of 15 l for an average small family size was designed, developed, and fabricated for canal water potability. The volume and thickness of filter media were computed and found to be 4,544 cm3 and 5.6 cm, respectively. The provision for injection of sodium hypochlorite solution was made for the removal of bacterial contaminants and calibrated to be 1.5 mL for 15 l of water to maintain the required level of residual chlorine content (2–5 ppm) which was supplied through the pumping unit. The adsorbed contaminants on the filter media could be removed by placing them in 3 l of boiled water for 2 min. The experiment was conducted to determine the settlement duration of suspended solids in canal water and found to be 8 h, thereafter allowing it for filtration. The performance of the developed filter was evaluated by analyzing water quality parameters of the canal water before and after filtration. The values of BOD, chemical oxygen demand (COD), MPN, TDS, pH, and residual chlorine of filtered water were found to be within the permissible limit. The cost of the developed filter was estimated to be INR 1,300 which is economically viable, technically feasible, and easily portable.