Study of Degradation of Pharmaceutical Wastes in Water and Its Impact on Ecosystems

Pharmaceutical active ingredients (PhACs) are increasingly detected in surface water, groundwater, and wastewater systems worldwide due to continuous consumption, incomplete metabolism, and inadequate removal during wastewater treatment. This manuscript evaluates the occurrence, degradation pathways, and ecological impacts of pharmaceutical wastes in aquatic environments using published global monitoring data. Statistical evaluation of reported concentrations, wastewater treatment plant (WWTP) removal efficiencies, and ecological risk indicators is presented. Results indicate that several commonly used pharmaceuticals persist at ng/L–µg/L levels, with approximately one-quarter of monitored sites globally exceeding predicted no-effect concentrations (PNECs). Conventional WWTPs show variable removal efficiencies (10–80%), while advanced treatment technologies can achieve removals exceeding 90%. Ecological evaluation highlights chronic sub-lethal effects on aquatic organisms and increasing risks of antimicrobial resistance. Statistical analyses, including analysis of variance (ANOVA), regression modelling, and ecological risk assessment using risk quotients (RQ), were employed to evaluate spatial, seasonal, and anthropogenic influences. Results demonstrate significant seasonal variability (p < 0.05), strong correlation between population density and pharmaceutical concentrations (R² ? 0.7), and moderate to high ecological risk for antibiotics and antiepileptics. The findings highlight the limitations of conventional treatment systems and emphasize the need for advanced treatment technologies and regulatory interventions to mitigate ecological risks. The study emphasizes the need for standardized monitoring, mixture toxicity assessment, and integration of advanced treatment technologies to mitigate pharmaceutical pollution.