Teklehaimanot G.Z., Kamika I., Coetzee M.A.A., Momba M.N.B.
Department of Environmental, Water and Earth Sciences, Water Care Unit, TUT, Private Bag X680, 175 Nelson Mandela Drive, Arcadia Campus, Pretoria, South Africa
Teklehaimanot, G.Z., Department of Environmental, Water and Earth Sciences, Water Care Unit, TUT, Private Bag X680, 175 Nelson Mandela Drive, Arcadia Campus, Pretoria, South Africa; Kamika, I., Department of Environmental, Water and Earth Sciences, Water Care Unit, TUT, Private Bag X680, 175 Nelson Mandela Drive, Arcadia Campus, Pretoria, South Africa; Coetzee, M.A.A., Department of Environmental, Water and Earth Sciences, Water Care Unit, TUT, Private Bag X680, 175 Nelson Mandela Drive, Arcadia Campus, Pretoria, South Africa; Momba, M.N.B., Department of Environmental, Water and Earth Sciences, Water Care Unit, TUT, Private Bag X680, 175 Nelson Mandela Drive, Arcadia Campus, Pretoria, South Africa
This study investigated the effects of population growth on the performance of the targeted wastewater treatment plants in Sedibeng District and Soshanguve peri-urban area, South Africa. The impact of population growth was assessed in terms of plant design, operational capacity (flow rate) and other treatment process constraints. Between 2001 and 2007, the number of households connected to the public sewerage service increased by 15.5, 17.2 and 37.8 % in Emfuleni, Lesedi and Midvaal Local Municipalities, respectively. Soshanguve revealed a 50 % increment in the number of households connected to the sewerage system between 1996 and 2001. Except for Sandspruit (−393.8 %), the rate of influent flows received by Meyerton increased by 6.8 ML/day (67.8 %) and 4.7 ML/day (46.8 %) during the dry and wet seasons, respectively. The flow rate appeared to increase during the wet season by 6.8 ML/day (19.1 %) in Leeuwkuil and during the dry season by 0.8 ML/day (3.9 %) in Rietgat. Underperformance of the existing wastewater treatment plants suggests that the rapid population growth in urban and peri-urban areas (hydraulic overloading of the wastewater treatment plants) and operational constraints (overflow rate, retention time, oxygen supply capacity of the plants and chlorine contact time) resulted in the production of poor quality effluents in both selected areas. This investigation showed that the inefficiency of Meyerton Wastewater Treatment Plant was attributed to the population growth (higher volumes of wastewater generated) and operational constraints, while the cause of underperformance in the other three treatment plants was clearly technical (operational). © 2015, Springer Science+Business Media New York.
Chemicals removal (water treatment); Effluents; Flow rate; Nitrification; Oxygen supply; Population statistics; Reclamation; Sewage pumping plants; Sewers; Toxicity; Urban growth; Water pollution; Water treatment; Water treatment plants; Dry and wet seasons; Operational capacity; Operational constraints; Population growth; Rapid population growth; Sewerage services; Treatment process; Wastewater treatment plants; Wastewater treatment; chlorine; nitrate; phosphate; phosphorus; storm water; absorption; activated sludge; aeration; aquatic environment; Article; bacterial growth; chemical oxygen demand; chlorination; climate; concentration (parameters); controlled study; denitrification; disinfection; environmental sanitation; Escherichia coli; flow rate; health hazard; household; human; nitrification; nonhuman; oxidation; oxygenation; population growth; population size; public health; seasonal variation; sedimentation rate; sewage effluent; South Africa; suspended particulate matter; waste water management; waste water treatment plant; water pollution