Persistent Organic Pollutants (POPs) Removal by Drinking Water Treatment Plants. (DWTPs): A Case Study of the Buffalo River Catchment

Abstract

The Buffalo River is the main source of potable water for residents of King William's Town, Bisho, and Mdantsane hence it is key for public health. It therefore follows that the well-being of the local population is a function of the quality of the water provided by drinking water treatment plants (DWTPs) like the Umzonyana Drinking Water Treatment Plant which sources its raw water from the Buffalo River. Persistent Organic Pollutants (POPs), including organochlorine pesticides (OCPs), organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) are probable contaminants that may potentially pollute both raw and treated water

Assessment of the efficiency of DWTPs in removing these pollutants is important. This research delves into the problem of finding out the removal efficiency of POPs by DWTPs in the Buffalo River catchment, with a focus on the Umzonyana Water Treatment Plant.

The aim of this research was to evaluate the effectiveness of the Umzonyana Water Treatment Plant in removing POPs from the Buffalo River source water. The study especially sought to understand the removal or persistence of POPs in the water treatment process and do an assessment on the potential implications for public health.

The methodology involved collecting raw and treated water samples from the Buffalo River and the Umzonyana Water Treatment Plant. The collected samples were analysed using Gas Chromatography-Mass Spectroscopy (GC-MS) in the identification and quantification of various POPs concentrates. The analysis provided information into the occurrence of PAHs, PCBs, and OCPs in both the raw and treated water.

The results of the GC-MS analysis indicated that the concentrations of POPs in both raw and treated water were within the regulatory limits of established standards, thereby suggesting that the Buffalo River may be experiencing minimal contamination from POPs. This likely may be arising from limited industrial discharge, agricultural runoff, or other pollution sources. Furthermore, the treatment methodologies at the Umzonyana Water Treatment Plant are apparently effective in reducing the concentration of these contaminants, with levels falling below detectable limits. Notwithstanding these positive findings, it was picked up that the staff at the Umzonyana Water Treatment Plant possess adequate knowledge in general water treatment processes but had limitations in their understanding of POPs removal, since they do not routinely monitor for these pollutants.

Based on the findings, this dissertation recommends continued monitoring and analysis of both the source and treated water from the Buffalo River and the Umzonyana Water Treatment Plant respectively. More sensitive methodologies should be employed to detect trace amounts of POPs, and long-term monitoring of source water quality should be implemented. Future studies should explore a broader range of POPs, evaluate the removal efficiencies under varying water quality conditions, and develop enhanced analytical techniques for POP detection. It is recommended additionally that an enhanced training program for plant staff regarding POPs and their removal be introduced, alongside investment in modern technologies and collaboration with researchers and policymakers to ensure optimal POP removal and public health.