Evaluation of chlorination efficiency on improving microbiological and physicochemical parameters in water samples available in Sheble Berenta district Amhara region, Ethiopia

Chlorination is the most common method of water disinfection of pathogens before discharged into receiving streams, rivers, or oceans. This study evaluates chlorination efficiency in improving microbiological and physicochemical parameters in water samples available in the Sheble Bernta district, Amhara region, from May 2020 to June 2020. Water samples were collected from selected five sampling points from unprotected springs, groundwater, hand-dug well, and river in five kebele from the district. All samples were undergone sample preparation. The chlorination process was made by calcium hypochlorite and then analyzed for bacteriological and physicochemical parameters before and after chlorination using standard procedures. The results of this study before chlorination showed that total coliform (TC) of water ranged between 71 and 127,000 (CFU)/100 ml, pH = 6.89-.35, turbidity = 196–270 NTU, and total dissolved solid (TDS) = 315–404 mg/l. Then the result of the microbiological and physicochemical parameters of water after chlorination was changed into total coliform ranging between1 50 (CFU)/100 ml, pH = 7.25–8.10, and turbidity = 2.9–5.6 NTU, TDS = 93–134 mg/l. Finally, the result confirmed that the removal efficiency of chlorination in total coliform (TC), turbidity, and TDS was ranged between 98.29 and 99.99%, 97 and 92-98.61%, and 62.03 and 73.31%, respectively. It was observed that there is a significant difference in removing turbidity, electrical conductivity, and total dissolved solids (TDS) before and after chlorination, but the pH test did not show a significant difference (p < 0.05). The efficiency of chlorination in removing total coliform and impurity of water is very efficient. It plays a vital role in the bactericide effect, reducing turbidity, and water's total dissolved solids. However, chlorinated compounds' (Ca(OCl)2) increased the pH of water after treatments. This study concluded that the efficiency of chlorination in improving the quality of water is highly significant (p < 0.05) and made water under permeable level compared to the World Health Organization standard. Hence, the chlorination water treatment process in a household can be granted to get quality water at the household level.