The Persistence of Refractory Pharmaceuticals in Aquatic Systems and Their Environmental Impacts

Abstract

This study investigates the occurrence and persistence of pharmaceutical residues in wastewater, with particular emphasis on treatment methods including nanofiltration, microbial biodegradation, constructed wetlands, and titanium dioxide (TiO₂) photocatalysis. Most of these approaches achieve elimination rates exceeding 70% for specific pharmaceuticals. However, notable limitations remain: microbial biodegradation is highly sensitive to environmental factors such as temperature, pH, and nutrient availability, leading to variability across seasons and locations; TiO₂ photocatalysis requires ultraviolet light excitation and is hindered by light scattering, shielding effects, and interference from natural organic matter and inorganic ions. These findings underscore the urgent need for more robust and scalable solutions to mitigate the environmental risks posed by pharmaceutical contamination in aquatic systems.