A two-year study of emerging micro-pollutants and drugs of abuse in two Western Cape wastewater treatment works (South Africa). (December 2021)

• Record Type: Journal Article
• Authors: Archer, Edward; Volschenk, Mercia; Brocker, Ludwig; Wolfaardt, Gideon M.
• Is Part Of: Chemosphere. Volume 285(2021)
• Publication Date: 2021-12
• Subjects: Pharmaceuticals -- Illicit drugs -- Mass balance -- Wastewater-based epidemiology -- Environmental risk assessment; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.131460
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: This study evaluated the occurrence and fate of fourteen contaminants of emerging concern (CECs) at two South African wastewater treatment works (WWTW). Daily loads of the drug targets were calculated in the aqueous phase of influent- and effluent wastewater to evaluate their fate at the treatment works, along with population-normalised daily loads in raw influent wastewater to identify community-wide substance use patterns in the two study areas. Environmental risk characterisation of the CECs at WWTW effluent discharge was done using conventional risk quotient (RQ) estimations. A significant reduction of most CECs was observed at both WWTW locations, except for some that have been previously recorded to persist through various WWTW processes globally, including the illicit drug methaqualone that was reported here for the first time to evaluate its fate during wastewater treatment, substance use trends, and potential toxicological risk. Moderate-to high-RQs were estimated for several target CECs during the sampling period for both treatment facilities. The results presented here suggest the need for a multi-disciplinary approach to WWTW monitoring of CECs and highlight the need for further refinement of risk assessment approaches to mitigate recalcitrant- or pseudo-persistent CECs in wastewater discharge. Such refinement should include: (1) identifying the potential ecological risk on a wider range of sentinel indicators, (2) interaction of CECs with various biochemical pathways (including sub-lethal toxicity responses), (3) identifying the persistence and toxicological risks of breakdown products and (4) partitioning of CECs in the aqueous environment and/or bioaccumulation in freshwater biota. Graphical abstract: Image 1 Highlights: Occurrence of 14 CECs at two South African WWTWs over a period of two years. A novel report on the presence and fate of the illicit drug methaqualone in WWTWs. Population-normalised daily load estimates of consumed drugs in the study areas. Moderate-to high toxicity risk estimations of selected CECs in the WWTW effluents.