Monitoring the performance of two wastewater treatment plants in the treatment of selected antiretrovirals in the Gauteng Province, South Africa

South Africa is classified as one of the countries in Africa with the highest number of people living with human immunodeficiency virus (HIV). This has led to a rapid increase in the utilization of antiretroviral drugs (ARVDs) and their ultimate disposal in the environment and surface waters, and these ARVDs end up in wastewater treatment plants (WWTPs). Therefore, this study aimed to monitor selected ARVDs (lamivudine, dolutegravir, efavirenz, lopinavir, nevirapine, and emtricitabine) in two WWTPs in the Gauteng Province, South Africa. Wastewater samples were collected in summer and spring from the two WWTPs. The samples were extracted using solid-phase extraction and analyzed using Liquid Chromatography Mass Spectrometry. In summer, the influent concentrations of targeted ARVDs from WWTP1 ranged from 0.285 - 3.90 ng/mL, while in WWTP2, it was 1.18–7.28 ng/mL, while the effluent concentrations ranged from n.d.–0935 ng/mL for WWTP1 and n.d.–0.24 ng/mL for WWTP2. In winter, the influent concentrations of targeted ARVDs from WWTP1 ranged from 0.505 - 6.98 ng/mL, while in WWTP2, it was 1.47–9.18 ng/mL, while the effluent concentrations ranged from n.d.–1.095 ng/mL for WWTP1 and 0.01–0.93 ng/mL for WWTP2. The performance of WWTP1 in summer and winter ranged from 76 % to 100 % and 70–100 %, respectively, while WWTP2 achieved 97–100 % and 96–100 %, respectively. The data shows that the two WWTPs are performing well in the treatment of the selected ARVDs.