The microbiological qualities of the final effluents of two wastewater treatment facilities in the Eastern Cape Province of South Africa were investigated using clostridia as surrogate indicators. Relevant physicochemical parameters were also assessed. Temperature (15-20oC), pH (5.3-8.1), salinity (0.15-0.25 psu), conductivity (278-464 µS/cm) and total dissolved solids (TDS) (139-232 ppm) of the final effluents were well within the recommended limits of no risks. However, dissolved oxygen (DO) (0.94-6.60 mg/l) and the turbidity (2.04 – 310 NTU) did not comply with the standard guidelines for the protection of aquatic ecosystems. High levels of vegetative cell counts (0-2.3×105 cfu/100ml) and spore counts (0-2.9×104 cfu/100ml) were obtained for sulphite reducing clostridia (SRC) in most samples collected from the final effluents of the two treatment plants which exceeded the set No Observed Adverse Effect Levels (NOAELs). The need for regular monitoring of the activities of wastewater treatment facilities in rural communities of the Eastern Cape Province for compliance to regulatory standards is therefore advocated.
Clostridium, Surrogate indicators, Wastewater treatment plant, Pollution
© The Author(s) 2012. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License which permits unrestricted use, sharing, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.