Advanced oxidation processes for the removal of antidepressants from wastewater: a comprehensive review

Pharmaceutical contaminants, particularly antidepressants, have emerged as a critical environmental concern due to their persistence in aquatic ecosystems and potential toxicological effects. Despite partial removal through conventional wastewater treatment plants (WWTPs) and sewage treatment plants (STPs), residual concentrations ranging from nanograms to micrograms per liter persist, leading to adverse ecological consequences. Studies have demonstrated that even trace levels of selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) can disrupt the physiological and behavioral processes of aquatic organisms, contributing to bioaccumulation and long-term ecological imbalances. Conventional techniques fail to achieve complete mineralization of antidepressants, necessitating the development of advanced remediation strategies. Advanced Oxidation Processes (AOPs) have emerged as a promising alternative, utilizing highly reactive species such as hydroxyl radicals (˙OH) and sulfate radicals (SO₄˙^-) to degrade complex pharmaceutical residues into harmless byproducts. This review systematically examines the sources, pathways, and environmental impact of antidepressants in water bodies while evaluating the efficiency and applicability of AOPs for their removal. A critical comparison of various AOPs, including photocatalysis, Fenton-like processes, ozonation, and sulfate radical-based oxidation, highlights their effectiveness in degrading antidepressants. The review discusses energy demand, byproduct formation, and cost-effectiveness, and proposes future perspectives for optimizing AOPs to enhance environmental sustainability.