Suitability of pond sand filter as an alternative safe drinking water technology at the sundarban region, Bangladesh

Abstract

Water is the most important thing for the survival of human beings because man cannot live without water for a single moment. The coastal region of Bangladesh faces pure drinking water crisis due to saline water intrusion and iron content of tube wells where pond sand filter (PSF) is using as alternative water supply system of southwestern coastal region specially Sudarban region of Bangladesh. This study was conducted to assess the quality of water and evaluate and compare the performance of these technologies at Mongla Upazila of Bagerhat District. For this purpose 24 water samples from six PSFs, eight protected pond (PP) and two reverse osmosis (RO) were collected and analyzed in the pre monsoon season. Different physico-chemical and biological parameters such as pH, electrical conductivity (EC), total dissolved solid (TDS), salinity, turbidity, ammonium (NH4+), total hardness, total alkalinity, Chloride (Cl-), total coliform and fecal coliform were measured both in PSFs and PP water. The pH, ammonium, total hardness, total alkalinity, chloride, phosphate, sulphate and nitrate value (average) of PSFs have been decreased by 7.67, 0.16mg/l, 236mg/l, 137mg/l, 228mg/l, 0.09mg/l, 32.83mg/l and 4.95mg/l respectively than the concerned pond and meet the Bangladesh standard. Though the presence of any coliform bacteria in the drinking water is harmful for human health, 58.33% of the PSFs (studied) contain fecal coliform. The study proves that PSFs is unable to treat the highly fecal coliform contaminated water. Disinfection before supplying water should be adopted to ensure the bacteria free drinking water.