EVALUATION OF THE TREATMENT EFFICIENCY OF MUST WASTEWATER TREATMENT PLANT: A CASE STUDY ON MUST CAMPUS

Malawi is water scarce country in terms of quality with maximum rainfall received in the summer season which lasts for only three months (November, December and January); hence the water resources have to be protected. The municipal wastewater effluents are considered one of the environmental threats that impact the water quality of the streams. This study was conducted to evaluate the treatment efficiency of the MUST wastewater treatment plant. The study focused mainly on primary data which was collected and analyzed using the standard methods of laboratory analysis. The standard methods used include colorimetric method for measuring COD, Photometric method which measures TSS, turbidity and ammonia and the aqua multimeter probe which was used to take in-situ measurement of parameters including temperature, pH, ORP, EC and Salinity. The data set using ten water quality parameter (ammonia, BOD, TSS, COD, ORP, EC, turbidity, pH, temperature, salinity) was measured from influent and effluent of the MUST wastewater treatment plant using grab sampling technique

Physical, chemical and microbiological efficiency of MUST Sewage/Wastewater Treatment Plant was determined. This was done by studying the applied technology and comparing analyzed results of its influent and effluent with that of regulatory set limits of the Malawi Bureau of standards and World Health Organization (WHO). The result obtained from the samples collected from the influent of the MUST Sewage/wastewater Treatment Plant, showed that the Sewage/Wastewater quality was contaminated and the result of its Effluent showed that the sewage treatment Plant was not very effective and efficient, because it was not able to bring all the stated parameters to be within tolerance limits for industrial effluents. The Total Suspended Solid (TSS), ammonia, five-day Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), Total Dissolved Solids (TDS), Turbidity, Conductivity and in the influent were far above the regulatory set limits so as the effluents. This shows that the treatment plant is not able to satisfactorily reduce the highly polluted influent within the regulatory limits after treatment thus making the effluent not environmentally friendly. It is advised that combined sewage treatment technology as used by the MUST Sewage treatment Plant should be improved for efficient treatment. Performance appraisal has been carried out by comparing the concentrations of pollutants at the inlet and outlet of the treatment unit. The grab samples were collected at the inlet and outlet of all the treatment units and analyzed as outlined in the standard methods for the examination of water and wastewater. The samples were analyzed for various parameters like pH, BOD, COD, TSS and TDS, ORP, ammonia depending on the results, performance of the plant was evaluated. The study highlighted that the MUST Wastewater Treatment Works (WWTW) is somehow not effectively treating the wastewater up to the required standards before discharging them into the downstream rivers. This study concludes that the MUST WWTW may contribute significant loads of pollutants into these rivers including Ndelerani stream that drains into Chimvu which commonly used by the surrounding communities