Performance and Loading of Domestic Wastewater Treatment Plants Receiving Aquaculture Processing Effluent.

This study dealt with the loading and performance of a domestic wastewater treatment plant when receiving combined influent from an aquaculture processing factory and an urban settlement in Kariba town, Zimbabwe. The methodological framework was a case study approach involving a local aquaculture factory and two treatment plants. In the study effluent from Nyamhunga treatment plant, which receives both domestic and aquaculture effluent, acted as the treatment. Effluent from a similarsized plant, Mahombekombe treatment plant, which only receives domestic wastewater acted as the control. Influent and effluent samples from both plants were collected over a 6 months period. Effluent samples were also taken from the aquaculture factory. The samples were analyzed for Chloride, TotalNitrogen, Biological Oxygen Demand and Fats, Oils and Grease using standard laboratory techniques. Research findings show that Mahombekombe treatment plant was more efficient than Nyamhunga treatment plant. Nyamhunga treatment plant effluent registered significantly higher concentrations for all tested parameters compared to Mahombekombe treatment plant. Effluent from the aquaculture factory significantly increased the wastewater load received by Nyamhunga treatment plant, in both volume and composition. The findings of the study suggests that coupling treatment plants to aquaculture processing facilities might not be a good practise since the former increases the load and concentrationsof wastewater significantly affecting performance.