Mining wastewater can have adverse effects on the ecosystem; thus, treatment before discharging into the environment is of utmost importance. This manuscript reports on the effect of mining wastewater on the environment. Moreover, the currently used, effective and commercialised mine wastewater treatment technologies such as SAVMIN®, SPARRO®, Biogenic sulphide, and DESALX® are reported in this study. These technologies integrate two or more separation processes, which have been proven to be effective for the high recovery of salts and water for reuse. Some of the technologies reported can significantly recover salts and >95% of water. Modern pilot-stage and laboratory-scale treatment systems used for the recovery and removal of metals are also reported herein. Since some treatment technologies can generate highly toxic sludge and other waste products, the management of the generated waste was also considered. Some studies have focused on the treatment of wastewater at the laboratory level using the adsorption process. Most adsorbents exhibit promising results; however, there is insufficient research on reusability, toxic sludge management, and the economic analysis of the systems. Moreover, the implementation of adsorption systems in wastewater is necessary. Furthermore, the integration of treatment systems to recover precious metals at low concentrations is desirable in addition to water reclamation to achieve circular mine water.

Composite polyethersulfone (PES) membranes containing N-aminoethyl piperazine propane sulfonate (AEPPS)-modified graphene oxide (GO) were integrated with either of the two pretreatment processes (activated carbon (AC) adsorption or polyelectrolyte coagulation) to assess their effectiveness in mitigating membrane fouling during the treatment of abattoir wastewater. The AEPPS@GO-modified membranes, as compared to the pristine PES membranes, showed improved hydrophilicity, with water uptake increasing from 72 to 118%, surface porosity increasing from 2.34 to 27%, and pure water flux (PWF) increasing from 235 to 673 L.m⁻²h⁻¹. The modified membranes presented improved antifouling properties, with the flux recovery ratio (FRR) increasing from 59.5 to 93.3%. This study compared the effectiveness of the two pretreatment processes, AC, coagulation, and the integrated system (coagulation/AC-UF membrane), in the removal of natural organic matter (NOM) and improvement of abattoir wastewater’s pH, electrical conductivity, TDS, and turbidity. The integrated systems produced improved water quality in terms of pH, EC, TDS, turbidity, and organic content. The fluorescence excitation–emission matrix (FEEM) analysis exhibited almost no fluorescence peak post-treatment following organic loading removal. The quality of the water met the South African non-potable water reuse standards. The sole membrane treatment systems exhibited good fouling resistance without the pretreatment systems; however, integrating these systems can offer extended longer filtration periods, thereby assisting in cost aspects of the abattoir wastewater treatment system.

Municipal wastewaters pose a severe risk to the environment and human health when discharged untreated. This is due to their high content of pathogens, such as viruses and bacteria, which can cause diseases like cholera. Herein, the research and development of porphyrin-modified polyethersulfone (PES) ultrafiltration (UF) membranes was conducted to improve bacterial inactivation in complex municipal wastewater and enhance the fouling resistance and filtration performance. The synthesis and fabrication of porphyrin nanofillers and the resultant membrane characteristics were studied. The incorporation of porphyrin-based nanofillers improved the membrane’s hydrophilicity, morphology, and flux (247 Lm⁻² h⁻¹), with the membrane contact angle (CA) decreasing from 90° to ranging between 58° and 50°. The membrane performance was monitored for its flux, antifouling properties, reusability potential, municipal wastewater, and humic acid. The modified membranes demonstrated an effective application in wastewater treatment, achieving notable antibacterial activity, particularly under light exposure. The In-BP@SW/PES membrane demonstrated effective antimicrobial photodynamic effects against both Gram-positive S. aureus and Gram-negative E. coli. It achieved at least a 3-log reduction in bacterial viability, meeting Food and Drug Administration (FDA) standards for efficient antimicrobial materials. Among the variants tested, membranes modified with In-PB@SW nanofillers exhibited superior antifouling properties with flux recovery ratios (FRRs) of 78.9% for the humic acid (HA) solution and 85% for the municipal wastewater (MWW), suggesting a strong potential for long-term filtration use. These results highlight the promise of porphyrin-functionalized membranes as multifunctional tools in advanced water treatment technologies.

Metal-organic frameworks (MOFs) refer to porous materials which have received excessive interest due to their unique structural diversity thus helping them maintain high surface area and porosity. Zirconium-based MOFs (UiO-66) can be easily modified with various functional groups, allowing control over how strongly an analyte binds to the MOF. Amine-functionalized UiO-66 MOFs (UiO-66-NH ₂ ) offers higher surface areas and exceptional porosity with potentially enhanced activity compared to traditionally used materials such as base metal oxides and offer shape/size selectivity, which attracts many applications such as gas storage, gas purification and separation, wastewater treatment. In recent studies, UiO-66-NH ₂ has been incorporated with nanomaterials such as graphene oxide (GO) (UiO-66-NH ₂ /GO) to improve its properties for adsorption applications. In this review, we present the synthetic methods, characteristic properties, and adsorption/separation applications of amine-functionalized zirconium-based metal-organic frameworks as well as incorporation of these MOFs in polymeric membranes. Lastly, challenges and future perspectives of UiO-66-NH ₂ /GO MOFs are discussed.

The growing demand for critical materials such as lithium, nickel, cobalt, and manganese in electric vehicles, renewable energy systems, and advanced electronics has intensified the need for sustainable recovery strategies. Spent lithium-ion batteries, mineral tailings, and industrial by-products represent valuable secondary resources that can support circular economy objectives. However, conventional hydrometallurgical and pyrometallurgical processes are energy-intensive, chemically demanding, and often generate significant secondary waste, including sludge and saline effluents. Membrane-based separation technologies have emerged as promising alternatives due to their modular design, lower energy requirements, and potential for selective metal recovery. Pressure-driven processes, including ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO), as well as electro-driven systems such as electrodialysis (ED), enable target separations (e.g., Li/Mg, Co/Ni, Li/Co-Ni-Mn) through size exclusion, charge-based selectivity, and ion-membrane interactions. Nevertheless, membrane performance in realistic leachates characterized by low pH, high ionic strength, oxidants, and complex metal speciation is strongly governed by chemistry-driven failure modes. These include inorganic scaling (e.g., gypsum and silica), metal hydroxide precipitation, colloidal and organic fouling, redox-induced instability, and polymer degradation, which collectively contribute to flux decline, selectivity loss, and reduced membrane lifetime. This review critically evaluates membrane applications for battery and mineral waste valorization, linking dominant failure mechanisms to solution chemistry and long-term stability. Techno-economic considerations are discussed using normalized metrics (kWh/m ³ , kWh/kg metal, $/kg product), highlighting conditions under which membranes can become cost-competitive with conventional extraction routes.