The screening of emerging micropollutants in wastewater in Sol Plaatje Municipality, Northern Cape, South Africa

• Published in: Environmental pollution (1987) 2022-12, Vol.314, p.120275-120275, Article 120275
• Main Authors: Oluwalana, Abimbola E., Musvuugwa, Tendai, Sikwila, Stephen T., Sefadi, Jeremia S., Whata, Albert, Nindi, Mathew M., Chaukura, Nhamo
• Format: Article
• Language: English
• Subjects: Modelling; Orbitrap mass spectrometry; Pesticides; Pharmaceuticals; Recreational drugs; Sampling; Wastewater
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2022.120275

Although pollutants pose environmental and human health risks, the majority are not routinely monitored and regulated. Organic pollutants emanate from a variety of sources, and can be classified depending on their chemistry and environmental fate. Classification of pollutants is important because it informs fate processes and apposite removal technologies. The occurrence of emerging contaminants (ECs) in water bodies is a source of environmental and human health concern globally. Despite being widely reported, data on the occurrence of ECs in South Africa are scarce. Specifically, ECS in wastewater in the Northern Cape in South Africa are understudied. In this study, various ECs were screened in water samples collected from three wastewater treatment plants (WWTPs) in the province. The ECs were detected using liquid chromatography coupled to high resolution Orbitrap mass spectrometry following Oasis HLB solid-phase extraction. The main findings were: (1) there is a wide variety of ECs in the WWTPs, (2) physico-chemical properties such as pH, total dissolved solids, conductivity, and dissolved organic content showed reduced values in the outlet compared to the inlet which confirms the presence of less contaminants in the treated wastewater, (3) specific ultraviolet absorbance of less than 2 was observed in the WWTPs samples, suggesting the presence of natural organic matter (NOM) that is predominantly non-humic in nature, (4) most of the ECs were recalcitrant to the treatment processes, (5) pesticides, recreational drugs, and analgesics constitute a significant proportion of pollutants in wastewater, and (6) NOM removal ranged between 35 and 90%. Consequently, a comprehensive database of ECs in wastewater in Sol Plaatje Municipality was created. Since the detected ECs pose ecotoxicological risks, there is a need to monitor and quantify ECs in WWTPs. These data are useful in selecting suitable monitoring and control strategies at WWTPs. [Display omitted] •An assortment of emerging contaminants were detected in wastewater.•The physicochemical properties of wastewater were improved by treatment.•Natural organic matter was predominantly non-humic, and removal was 35–90%.•Most of the emerging contaminants were recalcitrant to removal.•Pesticides, recreational drugs, and analgesics were frequently detected.