Urban expansion and its implication on domestic wastewater treatment in a typical small town of a developing country: case of Masvingo, Zimbabwe · Electronic Theses and Dissertations

Author

Zingi Godwin K

Title

Urban expansion and its implication on domestic wastewater treatment in a typical small town of a developing country: case of Masvingo, Zimbabwe

Abstract

Background: Rapid urbanisation and overpopulation influence the efficiency of the wastewater treatment plants particularly in small towns of developing countries. Objectives: The study investigated the impact of urban expansion on the efficiency of wastewater treatment in Masvingo town, Zimbabwe. Methods: Eight wastewater quality parameters (temperature, pH, TDS, NH3, PO43- turbidity, NO3-, BOD) were measured at three sampling sites (inlet, cascade and holding pond) for a period of 1 month from 27 May to 4 June 2022. Parameters were analysed using standard methods for water and wastewater analysis. Secondary data were used to augment primary data to determine whether the wastewater treatment plant (WWTP) was still working along design parameters. The variation of wastewater quality parameters across sampling sites were determined by one-Way ANOVA with GLM post hoc. Measured values were compared to national discharge limits using a one sample student t-test. The efficiency of the WTP was determined by the effluent removal efficiency and population equivalence. Analyses were performed in SPSS version 16.0, and variations considered significant at p < 0.05.
Key results: The WWTP was designed to treat 21 Ml/day of wastewater from a population of 110 000 as ta 2022 to meet national wastewater discharge standards. By 2022, the WTP was receiving of wastewater from an estimated population of of 110 000 which produced It was overloaded. The quality of effluent disposed of into xxx River did not meet national limits. These included TDS, Ammonia, phosphates, and turbidity significantly exceeded national limits at all sites (p < 0.05). Nitrates significantly exceeded the national limit at the holding pond and the cascade (p < 0.05). The efficiency of the WTP with respect to BOD in the disposed effluent was Mean%. Conclusion: Masvingo WTP had a treatment efficiency of 88% for BOD. The plant is overloaded by 10%. There is poor operation and maintenance characterised by higher concentration of nutrients being discharged into Mucheke which exceed EMA standards. Alternative wastewater treatment techniques requiring less technical expertise and operational costs may curb the problem of partially treated effluent into our waterways.

Date

May 2022

Publisher

BUSE

Keywords

Wastewater Treatment Plant (WWTP

Mucheke

BOD5

Supervisor

N/A