Regional disparities in PPCPs contamination of urban wastewater treatment plants: Unveiling influential factors and ecological effects

This study investigates the discharge of pharmaceuticals and personal care products (PPCPs) from wastewater treatment plants (WWTPs) into natural waters, highlighting a significant correlation with regional human activities. Despite the complexity of assessing factors influencing PPCPs sources, it remains underexplored. By conducting an extensive literature review of seven categories of PPCPs in WWTPs across five typical regions of China, the study reveals both similarities and disparities in PPCPs composition. Correlation analysis and four machine learning algorithms are employed to identify affecting factors for PPCPs emissions. The findings reveal that regional differences in per capita load are affected by treatment scale and population served by WWTPs. Economic indicators, wastewater treatment efficiency, and population age structure correlate with specific PPCPs. The RF algorithms demonstrated reliable predictive capabilities for PPCPs concentrations, identifying significant influencing factors such as service population, treatment capacity, and economic development. Ecological risk assessments indicate that certain PPCPs, such as norfloxacin (NOR) and ofloxacin (OFL), pose high risks to algae. These findings underscore the necessity for region-specific strategies to address PPCPs challenges, considering factors like economic development, urbanization, and demographic characteristics, and provide valuable insights into PPCPs presence and ecological risks.