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

Abimbola E Oluwalana; Tendai Musvuugwa; Stephen T Sikwila; Jeremia S Sefadi; Albert Whata; Mathew M Nindi; Nhamo Chaukura

doi:10.1016/j.envpol.2022.120275

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

Environ Pollut. 2022 Dec 1:314:120275. doi: 10.1016/j.envpol.2022.120275. Epub 2022 Sep 24.

Authors

Abimbola E Oluwalana¹, Tendai Musvuugwa², Stephen T Sikwila³, Jeremia S Sefadi⁴, Albert Whata³, Mathew M Nindi⁵, Nhamo Chaukura⁶

Affiliations

¹ Risk and Vulnerability Science Centre. Sol Plaatje University, Private Bag X5008, Kimberley, 8300, South Africa; Department of Physical and Earth Sciences, School of Natural and Applied Sciences. Sol Plaatje University, Private Bag X5008, Kimberley, 8300, South Africa.
² Department of Biological and Agricultural Sciences. Sol Plaatje University, Private Bag X5008, Kimberley, 8300, South Africa.
³ Department of Mathematical Sciences, School of Natural and Applied Sciences. Sol Plaatje University, Private Bag X5008, Kimberley, 8300, South Africa.
⁴ Department of Physical and Earth Sciences, School of Natural and Applied Sciences. Sol Plaatje University, Private Bag X5008, Kimberley, 8300, South Africa.
⁵ Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science, Engineering and Technology, University of South Africa, South Africa.
⁶ Department of Physical and Earth Sciences, School of Natural and Applied Sciences. Sol Plaatje University, Private Bag X5008, Kimberley, 8300, South Africa. Electronic address: nhamo.chaukura@spu.ac.za.

PMID: 36167166
DOI: 10.1016/j.envpol.2022.120275

Abstract

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.

Keywords: Modelling; Orbitrap mass spectrometry; Pesticides; Pharmaceuticals; Recreational drugs; Sampling; Wastewater.

MeSH terms

Environmental Monitoring / methods
Environmental Pollutants* / analysis
Humans
Illicit Drugs*
Pesticides* / analysis
South Africa
Waste Disposal, Fluid
Wastewater / chemistry
Water / analysis
Water Pollutants, Chemical* / analysis

Substances

Waste Water
Water Pollutants, Chemical
Pesticides
Environmental Pollutants
Illicit Drugs
Water