Ms Onele Gcilitshana

Level of Study: 
Assessment of physicochemical and microbiological qualities of wastewater final effluents: Komga and Reeston (East London) wastewater treatment plants as case studies

The present study is aimed at evaluating the physicochemical and microbiological qualities of the final effluents of two (Komga and Reeston) wastewater treatment plants in the Eastern Cape Province of South Africa. Microbiological parameters under review include faecal indicator bacteria, adenovirus, rotavirus, norovirus, enteroviruses, hepatitis A and hepatitis E viruses. The assessment of these parameters is done monthly over a projected period of one year, in order to assess the effect of seasonal changes on effluent qualities.  Samples have been collected for the first month (September 2012). For bacteriology, the incidence faecal coliforms has been assessed and not found in effluents from both plants while for virological assessment, samples have been concentrated by the adsorption elution method, preserved for nucleic acid extraction at -80⁰C. For physicochemical parameters, electrical conductivity (380–1242 mg/l), turbidity (19.1 NTU), free chlorine (0.44-6.5 mg/l) and phosphates (0.9-2.7 mg/l) were higher than the standards set by the Department of Water affairs. Turbidity ranged from 10.8 NTU-19.4NTU in effluents from both plants. However, the high chlorine residual concentration (0.44-6.5mg/l) demonstrated effectiveness in disinfecting the water since there were no faecal counts in the effluent samples.  In Reeston, there was high dissolved oxygen concentration (10.14 mg/l) and low biochemical oxygen demand (BOD) levels of 1 mg/l suggesting that the pollution levels were low. More samples will be collected and the viral genomes will also be quantified by Real-Time PCR.