Pollution of lower Manyame river with effluent from a water treatment plant, Zimbabwe · Electronic Theses and Dissertations

Author: Musara, Rejoice
Title: Pollution of lower Manyame river with effluent from a water treatment plant, Zimbabwe
Abstract: Rivers are the final sink of all pollution from watershed activities. Pollutants may enter the food chain to negatively affect the ecosystems. To determine the potential of lower Manyame River in Harare, Zimbabwe, using water quality indices, and estimate its self-purification capacity. Selected physicochemical parameters of river water and effluent from a water treatment plant (WTP) were measured to determine the potential pollution of the river using the weighted arithmetic water quality index (WAWQI). The river’s self-purification capacity was estimated over a stretch of 26.3km2 using the upstream-downstream dilution models. Samples were collected from March to May, 2025. Physicochemical analysis revealed significant pollution at the discharge point due to high concentrations of Al (26.6mg/l) and Fe (3.6mg/l). The WAWQI value for the discharge point 256.7 and the furthest point 500m from it 227.3 indicated very high pollution, respectively. The overall capacity of Manyame River to naturally attenuate the estimated pollution was found to be inadequate. Effluent from the WTP is polluting lower Manyame River which has a low self- urification capacity.
Date: May 2025
Publisher: BUSE
Keywords: Dilution model; Self-purification; water quality
Supervisor: Dr A Kanda