Application of Bio Sand Filters for improving drinking water quality in flood-affected areas of Pakistan, a case study of Shahdad Kot, Pakistan

Abstract

Flooding in the Shahdad Kot district has significantly impacted groundwater quality, compelling the resettled population to rely on surface water. Specifically, residents are using water collected in ponds from canals for their basic needs. However, the water from the canal carries a significant number of impurities and exhibits high turbidity due to sediment content, necessitating the analysis of key parameters including turbidity, total dissolved solids (TDS), pH, color, odor, and bacterial colonies such as E. coli. Data indicates that 78.5 % of households face exposure to E. coli contamination, 100 % of households are at risk from high turbidity levels, and 16.7 % of homes have water with unsafe pH levels. This study investigates the effectiveness of bio-sand filter (BSF) technology in treating contaminated drinking water in Shahdad Kot, Pakistan, following flooding, and examines the challenges and sustainability issues encountered during its implementation in this low-literacy area. Pre and Post testing of the water samples collected from each water pond are used to check the performance of BSF technology. Results indicate a substantial reduction in bacterial colonies, decreasing from over 50 to fewer than 5 colonies per 100 ml within three weeks, highlighting the effectiveness of the purification process. While TDS levels remain within World Health Organization (WHO) standards at less than 1000 mg/l, there is a notable improvement in turbidity levels, which have decreased dramatically from 450 NTU to 5 NTU in the pre and post-test results, also enhancing the color of the drinking water depicting the overall capability of BSF technology to improve the drinking water quality.

Keywords

• Bio sand filters
• Water quality
• Water ponds
• Shahdad Kot