Removal Efficiency of Faecal Indicator Organisms, Nutrients and Heavy Metals from a Peri-Urban Wastewater Treatment Plant in Thohoyandou, Limpopo Province, South Africa

International Journal of Environmental Research and Public Health

Joshua N. Edokpayi³  John O. Odiyo³  Titus A. M. Msagati²  Elizabeth O. Popoola¹ 

[1] Department of Chemical Sciences, Yaba College of Technology, P. M. B. 2011 Yaba, Lagos, Nigeria; E-Mail:;College of Science, Engineering and Technology, Nanotechnology and Water Sustainability Research Unit, Florida Science Campus, University of South Africa, 1710 Roodepoort, Johannesburg, South Africa; E-Mail:;Department of Hydrology and Water Resources, University of Venda, Private Bag X5050, Thohoyandou 0950, South Africa; E-Mail:

关键词: E. coli;    effluents;    health;    influent;    impacts;    treatment;    wastewater;   

DOI  :  10.3390/ijerph120707300

来源: mdpi

【 摘 要 】

Wastewater treatment facilities are known sources of fresh water pollution. This study was carried out from January to June 2014 to assess the reduction efficiency of some selected contaminants in the Thohoyandou wastewater treatment plant (WWTP). The pH and electrical conductivity of the effluent fell within the South African wastewater discharge guidelines. The WWTP showed the chemical oxygen demand reduction efficiency required by the Department of Water Affairs (DWA) guidelines of 75 mg/L for the months of April and June, although it was below this standard in March and May. Free chlorine concentration varied between 0.26–0.96 mg/L and exceeded the DWA guideline value of 0.25 mg/L. The concentration of nitrate-nitrogen (NO₃⁻ N) in the influent and effluent varied between 0.499–2.31 mg/L and 7.545–19.413 mg/L, respectively. The concentration of NO₃⁻ N in the effluent complied with DWA effluent discharge standard of 15 mg/L, except in April and May. Phosphate concentrations in the influent and effluent were in the ranges of 0.552–42.646 mg/L and 1.572–32.554 mg/L, respectively. The WWTP showed reduction efficiencies of E. coli and Enterococci during some sampling periods but the level found in the effluent exceeded the recommended guideline value of 1000 cfu/100 mL for faecal indicator organisms in wastewater effluents. Consistent removal efficiencies were observed for Al (32–74%), Fe (7–32%) and Zn (24–94%) in most of the sampling months. In conclusion, the Thohoyandou WWTP is inefficient in treating wastewater to the acceptable quality before discharge.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.