Advanced strategies for the removal of venlafaxine from aqueous environments: a critical review of adsorption and advanced oxidation pathways

Abstract

The persistence of venlafaxine (VEN), a widely prescribed antidepressant [1-[2-(dimethylamino)-1-(4-methoxyphenyl)ethyl]cyclohexan-1-ol], in aquatic environments raises serious concerns due to its chemical stability, bioaccumulation potential, and ecotoxicological impacts. Conventional wastewater treatment technologies are largely ineffective in eliminating such micropollutants, achieving removal efficiencies typically below 30%. This review critically evaluates and compares adsorption-based and advanced oxidation process (AOP)-based strategies for VEN removal from aqueous systems. Particular attention is given to adsorption mechanisms hydrophobic, π–π, electrostatic, and hydrogen-bonding interactions, using biochar, activated carbon, and emerging nanomaterials. Concurrently, state-of-the-art AOPs, including Fenton-like, photocatalytic, and persulfate-based oxidation, are analyzed with emphasis on radical generation, catalyst design, and operational optimization. Integrating heterogeneous catalysts such as metal oxide nanocomposites and graphene-based frameworks significantly enhances degradation kinetics, selectivity, and reusability under mild reaction conditions. Comparative analysis reveals that adsorption provides an eco-friendly, cost-effective pre-treatment, while AOPs enable complete mineralization and are ideal as polishing steps in hybrid treatment systems. This review offers the first comprehensive comparison of adsorption and advanced oxidation pathways for VEN removal, incorporating recent advances (2022–2024) and providing mechanistic insights, efficiency trends, and sustainability perspectives to guide future research on green wastewater remediation.