Tracking chemical releases in wastewater systems: An integrated plant-wide model for publicly owned treatment works

Publicly owned treatment works (POTWs) provide a vital service in treating wastewater from rural, urban, and industrial sources. The inflow of industrial wastewater to POTWs introduces a complex mixture of conventional and emerging contaminants, creating challenges for effective treatment and posing potential environmental and health risks. This study presents ChemTEAPOTW, a Python-based simulation model developed to track and estimate the fate and transport of chemicals of concern (CoC) in POTWs while also integrating inhalation and dermal occupational exposure pathways. The model comprehensively simulates chemical partitioning, removal processes, and environmental releases, incorporating sub-models for clarifiers, activated sludge reactors, anaerobic digesters, and sludge handling. Model predictions for CoC partitioning across air, water, biosolids, and biodegradation pathways showed strong agreement with literature-reported data, with approximately 75 % of values falling within one standard deviation of published means. By simulating the transport and fate of these CoC, this model serves as a valuable tool for designing, evaluating, and enhancing POTW operations. It provides a comprehensive understanding of end-of-life industrial material transfers to POTWs and describes the implications for environmental and public health impact assessments.