GREEN-SYNTHESIZED NANOPARTICLES FOR ENHANCED PHOTOCATALYTIC REMOVAL OF INDUSTRIAL POLLUTANTS FROM PAKISTAN’S WATER RESOURCES

Abstract

Industrial wastewater in Pakistan contains persistent organic pollutants and other contaminants that pose substantial risks to aquatic ecosystems and human health, while conventional treatment technologies may be constrained by high operational costs, incomplete degradation, and secondary waste generation. This study investigated the potential of green-synthesized nanoparticles for enhanced photocatalytic removal of industrial pollutants from contaminated water resources. Nanoparticles were synthesized using a biological route and characterized in terms of their structural, morphological, elemental, surface-chemical, and optical properties. Photocatalytic experiments were conducted under controlled conditions to evaluate the effects of catalyst dosage, pH, initial pollutant concentration, irradiation time, and light intensity. Treatment performance was assessed through pollutant-removal efficiency, degradation kinetics, COD and TOC reduction, and catalyst reusability. The results indicated that the green-synthesized nanoparticles achieved approximately 95% removal of the target pollutant under optimized conditions and demonstrated substantially greater performance than photolysis and dark-adsorption controls. The degradation data showed a strong fit to a pseudo-first-order kinetic model, while reductions in COD and TOC indicated substantial but incomplete mineralization. The catalyst retained considerable photocatalytic activity during repeated treatment cycles, demonstrating potential for reuse. The findings suggest that green-synthesized nanoparticles can provide an environmentally promising approach for advanced industrial wastewater treatment. However, further investigation of degradation intermediates, nanoparticle leaching, toxicity, long-term stability, solar operation, techno-economic feasibility, and pilot-scale performance is required before large-scale implementation in Pakistan.