STUDIES ON THE EFFICACY OF BRIDELIA FERRUGINEA BENTH BARK EXTRACT FOR DOMESTIC WASTEWATER TREATMENT

Abstract

The efficacy of Bridelia ferruginea Benth bark extract in wastewater treatment was investigated. Chemical analysis found the bark to contain potassium, sodium, calcium, magnesium, zinc, manganese, iron and copper. Phytochemical tests revealed the bark to contain tannins, phlobatannins, saponins, alkaloids, and steroids. Comparative studies using varying concentrations (0.5, 1.0, 2.5 and 5.0 % w/v) with alum and ferric chloride showed that the bark extract was effective in the clarification and sedimentation of total solids in the waste water sample. The optimum dose achieved was 2.5 % w/v with a minimum of 24 hours contact time. The total bacteria counts were reduced by 46 % after 24 hours when the extract was used whereas ferric chloride achieved 50 % reduction and alum achieved 55 % reduction under similar conditions. The feasibility of using the bark extract as an additional coagulant is therefore discussed. KEYWORDS: Bridelia ferruginea, Sedimentation, Total bacteria count, Wastewater treatment Bull. Chem. Soc. Ethiop. 2007, 21(2), 205-211.