Journal of Pure and Applied MicrobiologyVol. 6 No. 4

Clostridia as Surrogate Indicator of Water Quality: Two Wastewater Treatment Plants in South Africa as Case Study

M. Mubazangi1, M. Kolawole1, F. Aghdasi2 and A.I. Okoh1

1Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice 5700, South Africa. 2Risk and Vulnerability Assessment Centre, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa.

Received on 02 April 2012 and accepted on 14 May 2012

 

ABSTRACT

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 ÁS/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.

Keywords : Clostridium, Surrogate indicators, Wastewater treatment plant, Pollution.