Assessing the performance of Trichardt Wastewater Treatment Plant (South Africa)

Abstract

The main task in treating the wastewater in South Africa is to reduce the pollutants (solids, organic matter, nutrients, and micro-organisms) to meet the standard requirements from Department of Water and Sanitation (DWS). That means the discharged effluent should be without polluting the environment and posing safety risks. The objective of this study was to investigate the performance of the Trichardt Wastewater Treatment Plant (South Africa) and come up with recommendations for the improvement of the wastewater treatment plant. The performance of the plant was evaluated for its compliance with the standard set by the DWS. The water quality parameters tested include: Ammonia (NH3), Nitrate (NO3−), Phosphate (PO4−3), Chemical Oxygen Demands (COD), Turbidity (T) and Total Suspended Solids (TSS). The result indicates that the concentration of most of the considered parameters (TSS, NH4, COD, PO4−3) are above the permissible limit set by DWS throughout the year, except Nitrate. The operating flowrate is below the design capacity (1.8 m3/s) throughout the year, except September. Overall, the final effluent discharged to the stream do not comply with the standard set by DWS. Thus, measures for the improvement of the treatment plants’ performance are highly recommended. The increase of the hydraulic loading capacity and the use appropriate methods of treatment process such as biological nitrification-denitrification processes are suggested. The increase of retention time to 3 h and decrease of the screen openings to 12 mm are also highly recommended.