Background: Most of the rural populations in developing countries use surface water which is turbid and contaminated with human and animal faces. Water used for drinking purposes from these sources needs treatment to reduce the turbidity and pathogenic microorganisms and to protect the public health. Thus, this study aimed to determine the effectiveness of a natural coagulant, chickpea, in turbidity reduction of drinking water. Methods: A laboratory-based batch experimental study design was conducted from March 05–20, 2019. Synthetic turbid water was prepared from clay soil and surface water. Chickpea extract was used to determine its effectiveness in reducing turbidity in drinking water and was prepared following standard procedures. The PH, temperature, and turbidity were measured for each sample. The effectiveness of chickpea extract in turbidity reduction or removal was determined based on contact time, dose, temperature, and PH. Finally, the data obtained from laboratory analysis was subjected to analysis using Microsoft Excel, 2010. Result: In the current study, methanol extracted chickpeas removed turbidity up to 64.7% with an optimum dose of 1.5 ml/L at a contact time of 30 minutes. Chickpea was more effective at high levels of turbidity, with a turbidity reduction of 81.4%. With the increase of contact time, chickpea has reduced turbidity by up to 96%, which was nearly the same as with FeCl3. Furthermore, chickpeas were effective for medium and high turbidity water compared to low turbidity water to purify water. Conclusion: Use of natural coagulants should be encouraged as they are environmentally friendly, reduce turbidity, easily available, and less expensive. The study found that chickpeas could significantly stabilize colloidal matter, existing in synthetic turbid water, and reduced turbidity by up to 64.7% at 30 minutes of contact time, with 1.5 ml/l as the optimum dose.

Keywords: Turbidity, drinking water, natural coagulant, chickpea