Integrated Biosorption, Membrane Separation, and Advanced Oxidation Processes for Sustainable Wastewater Treatment: Mechanisms, Hybrid Systems, and Future Perspectives

Increased contamination and complexity of wastewater due to rapid industrialization, urbanization, and new contaminants have highlighted the limitations of conventional treatment technologies. The treatment of complex wastewater matrices containing heavy metals, refractory organic contaminants, pharmaceuticals, per- and polyfluoroalkyl substances (PFAS), nutrients, and pathogens requires an integrated treatment approach with complementary removal mechanisms. This review critically analyzes the principles, recent developments, and engineering applications of biosorption, membrane separation, and advanced oxidation processes (AOPs), and highlights their possible combination in hybrid wastewater treatment systems. Recent advances in engineered biosorbents, multifunctional membranes, and catalytic materials, including their mechanisms, material innovations, operational benefits, and limitations, are critically evaluated. Special focus is placed on the mechanistic synergy among the different technologies, showing how contaminant load reduction, membrane fouling mitigation, selective concentration, and oxidative degradation collectively improve treatment efficiency with reduction in energy and chemical consumption. This article also introduces a framework for process-engineered integrated hybrid treatment systems. Comparative analyses of hybrid configurations, engineering challenges, research gaps, and a decision support framework are provided to aid the selection of the technologies based on the wastewater characteristics and treatment objectives. New opportunities for artificial intelligence, digital process control, multifunctional materials, and circular resource recovery are also addressed. Overall, this review emphasizes that intelligently engineered hybrid systems integrating biosorption, membrane separation, and AOPs can be a promising pathway toward efficient contaminant removal, water reuse, resource recovery, and sustainable wastewater management.