Efficiency of Avocado Seed Extract as Natural Coagulant in Sustainable Purification of Drinking Water

There is an increasing need for affordable water treatment solutions especially in developing countries and natural coagulants as alternatives to conventional chemical coagulants with their attendant environmental and health implications, low effectiveness in low temperatures, high procurement cost, large sludge volumes and pH effects. An experimental study was conducted on efficiency of avocado seeds powder as a natural coagulant for drinking water purification. Avocado seeds contain bioactive compounds like tannins with known coagulating properties. A suspension of 5g/l of avocado seed extract prepared and used on raw untreated water samples from Lake Bunyonyi. Results showed optimum avocado seed extract dosage of 0.35mg/L reduced turbidity from 12.8 to 4.5 NTU, with removal efficiency of 65% and is in line with the Ugandan National Water Quality Standard for potable water. Colour was reduced from 30 to 13 PCU with removal efficiency of 57%. The pH of the treated water ranged from 7.0-7.4 for all samples while sludge volume was comparably very low. The avocado seed can be used as a natural coagulant at concentration and dosage comparable to conventional chemical coagulants. These findings suggest that avocado seed extract is a viable, eco-friendly, and cost-effective coagulant for rural household water purification systems. Key words: Avocado seed; Natural coagulant; Potable water; Optimum dosage