Limitations of wastewater treatment plants in removing trace anthropogenic biomarkers and future directions: A review.

This review highlights the limitations faced by conventional wastewater treatment plants (WWTPs) in effectively removing contaminants of emerging concern (CECs), heavy metals (HMs), and Escherichia coli (E. coli). This emphasises the limitations of current treatment methods and advocates for innovative approaches to enhance the removal efficiency. By following the PRISMA guidelines, the study systematically reviewed relevant literature on detecting and remedying these pollutants in wastewater treatment facilities. Conventional wastewater treatment plants struggle to eliminate CECs, HMs, and E. coli owing to their small size, persistence, and complex nature. The review suggests upgrading WWTPs with advanced tertiary processes to significantly improve contaminant removal. This calls for cost-effective treatment parameters and standardised assessment techniques to enhance the fate of MPs in WWTPs and WRRFs. It recommends integrating insights from mass-balance model studies on MPs in WWTP to overcome modelling challenges and ensure model reliability. In conclusion, this review underscores the urgent need for advancements in wastewater treatment processes to mitigate the environmental impact of trace anthropogenic biomarkers. Future efforts should focus on conducting comprehensive studies, implementing advanced treatment methods, and optimising management practices in WWTPs and WRRFs.