The focus of this review article was to outline the sources, pathways, effects, occurrence, and spatial distribution of the most prescribed pharmaceuticals in wastewater and receiving waters of South Africa. Google Scholar, Web of Science, and Scopus were used to gather data from different regions. A zone-wise classification method was used to determine the spatial distribution and data deficiencies in different regions of South Africa. This review revealed that over 100 pharmaceutical compounds have been reported in South Africa’s various water sources and wastewater, with most studies and highest concentrations being documented in Gauteng and Kwa-Zulu Natal. The pharmaceutical concentration in water samples ranged from ng/L to µg/L. Aspirin, ketoprofen, diclofenac, ibuprofen, naproxen, erythromycin, tetracycline, sulfamethoxazole, acetaminophen, streptomycin, ciprofloxacin, ampicillin, carbamazepine, atenolol, pindolol, efavirenz, and zidovudine residues were among the frequently detected pharmaceutical residues in water bodies and wastewaters of South Africa. Based on the spatial distribution data, Gauteng has the highest number of pharmaceuticals (108) detected in waste and surface water, with the Northern Cape having no monitoring evidence. Therefore, to precisely ascertain the geographical distribution of pharmaceutical contaminants in South Africa, this review recommends that further research be carried out to track their occurrence in aquatic environments and WWTP, especially in isolated regions like Limpopo.

This study aims to investigate the occurrence of efavirenz, levonorgestrel, ibuprofen, and diclofenac in wastewaters of Vhembe and Mopane District Municipalities, Limpopo Province, South Africa. A total of 48 samples were collected at the inlet and outlet of the selected wastewater treatment plants during April, July, and October 2023. The physicochemical parameters such as pH, electrical conductivity, total dissolved solids, and dissolved oxygen of the influent and effluent were determined in the field, while total organic carbon (TOC) and chemical oxygen demand (COD) were determined in the laboratory. The LC-20 prominence High-pressure liquid chromatography with a Photo-diode Array (PDA) detector was employed to quantify and profile the targeted pharmaceutical compounds. Levonorgestrel and efavirenz were analyzed using the gradient elution method, while the isocratic method was applied to analyze diclofenac and ibuprofen. The obtained results showed that the concentration ranges for ibuprofen were <LOD-114.00 μg/L (influent) and <LOD-59.9 μg/L (effluent), levonorgestrel: 6.2-8.09 μg/L (influent) and 4.25-20.9 μg/L (effluent), diclofenac: 2.21-25.00 μg/L (influent) and 0.36-5 μg/L (effluent), and efavirenz: 3.81-11.9 μg/L (influent) and 0.69-6.3 μg/L (effluent). The presence of these pharmaceutical contaminants in wastewater, particularly in effluent, requires attention as they may pose significant ecological threats in the receiving water bodies. Therefore, this study recommends the development of efficient wastewater treatment technologies targeting pharmaceutical compounds and further routine monitoring of these compounds in surface water resources, as well as understanding their fate and effects in aquatic organisms.

Water is regarded as an important natural resource to sustain life, and its purification is an important criterion that determines its quality and usefulness. In this study, the incorporation of Fe³⁺ oxide onto a phenylenediamine (pPD) polymer matrix through chemical co-polymerization was prepared, and its arsenite and fluoride removal potentials at optimal conditions from aqueous solution were evaluated. The morphology and structural analysis of the synthesized Fe-doped pPD (Fe-pPD) were comparatively evaluated using the FT-IR, SEM, EDS, and XRD techniques. Fe was successfully incorporated onto pPD matrix as confirmed by different morphological characterizations. The rate of adsorption of F⁻ and As³⁺ onto the Fe-pPD composite best followed the pseudo-second-order kinetic model. The experimental data for both As³⁺ and F⁻ onto the Fe-pPD composite better fit the Freundlich isotherm model at different operating temperatures. Overall, the synthesized composite exhibited a strong affinity towards fluoride uptake (96.6%) than arsenite uptake (71.14%) with a maximum capacity of 6.79 (F⁻) and 1.86 (As³⁺) mg/g. Additionally, the synthesized adsorbent showed some level of antimicrobial activity against common water-borne bacterial. Therefore, the Fe-doped pPD composite has the potential ability for inorganic metal species pollutants remediation and bacterial disinfection in community-level water purification processes.

This study aims to optimize the SPE parameters for purification and preconcentration of EFV and LVG to enable optimum detection and quantification by LC-20 Prominence High-Performance Liquid Chromatography (HPLC) system. The gradient elution method was used to profile and quantify efavirenz (EFA) and levonorgestrel (LVG). The optimized parameters were solution pH, solvent type and concentration, and elution volume. The 60 mg/3 mL Hydrophilic-lipophilic balance (HLB) was used to extract the target pharmaceutical contaminants. The percentage recoveries of EFA and LVG ranged from 67% to 83% and 70% to 94.61%, respectively at an optimal pH of 2, solvent concentration and type 100% Methanol and an elution volume of 4 mL using HLB cartridges. The method’s accuracy was validated by obtaining a correlation coefficient (R²) > 0.98 from the respective calibration curves of the target contaminants. The limit of detection (LOD) and limit of quantification (LOQ) for efavirenz were 0.705 µg/L and 0.14 µg/L, respectively, and for levonorgestrel, they were 0.061 µg/L and 0.199 µg/L. The optimized SPE method was used to extract wastewater samples, and the yield results showed that the method could be applied for the simultaneous detection of efavirenz and levonorgestrel, demonstrating its potential applications in environmental research. The concentration of EFA ranged from 0.36 to 8.10 µg/L in influent samples and 2.88 to 8.11 µg/L in effluent samples. Conversely, the concentration of levonorgestrel ranged from 2.64 to 32.31 µg/L in influent samples and 2.32 to 12.35 µg/L in effluent samples. The obtained results were validated by analyzing these samples using ultra-high-performance liquid chromatography. Based on the results, the optimized Solid Phase Extraction (SPE) method can be used to pre-concentrate EFA and LVG in wastewater samples, inspiring future research.

The presence of pharmaceutical compounds such as efavirenz and levonorgestrel in water resources has become an issue of great social and scientific concern in recent years due to their considerable effects on aquatic ecosystems and human health. This study aims to address this concern by synthesizing sulphur-doped carbon nanotubes (S-CNT) from macadamia nutshells for use in the efavirenz (EFA) and levonorgestrel (LVG) from an aqueous solution. The synthesized S-CNT was characterized for its functional groups, surface morphology, and crystallinity using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffractogram (XRD) techniques. SEM micrographs showed tubular features on the material’s surface. The efficiency of the synthesized S-CNT towards EFA and LVG removal was assessed using batch experiments in the presence of 250 nm UV. The maximum removal efficiencies for EFA and LVG were 99 and 98%, respectively, at optimum conditions of pH 2, dosage of 0.3 g/50 mL, and initial concentration of 2.5 ppm after 90 min agitation time. The removal of FEA and LVG involved both photodegradation and adsorption, wherein the EFA and LVG were degraded into C₁₄H₈ClF₃NO^± and C₁₃H₁₀ClF₃N^±; C₁₅H₂₁O₃‾ and C₂₁H₂₉O₃‾, respectively, by the UV light followed by their subsequent adsorption onto the surface of the S-CNT. The adsorption kinetics data yielded R² ≥ 0.98 for both pseudo-first-order and pseudo-second-order reaction kinetics models for both EFA and LVG, indicating the possibility of physisorption and chemisorption processes. The isotherm data fitted better to the Freundlich isotherm model, indicating that the removal occurred on a heterogeneous surface. Based on these findings, S-CNT can potentially remove EFV and LVG from wastewater.