LAUSR

Abstract In this paper, a regional spatial environmental multimedia modeling (RSEMM) approach is developed based on the integration of an environmental multimedia method (EMM) and a numerical water quality model. Emissions, inter-media mass transfer, physical transport and degradation processes are considered in the modeling system. The RSEMM approach is applied to the Beijing-Tianjin area in China, where there are many antibiotic emission sources throughout the Haihe River Basin including six streams. The antibiotic sulfadiazine (SDZ) is selected as the target contaminant in this basin region, including the urban area of Tianjin City. The predicted SDZ concentrations in the water and sediment zones align well with the reported monitoring data. A sensitivity analysis, using the Morris screening method, shows that flow rate and active sediment depth are the significant influential parameters for the regional water and sediment zones. Two modeling scenarios are further performed to assess health risks. They show that the SDZ concentrations and risks in the impacted environmental media could be reduced by possible mitigation actions. The RSEMM approach can also be applied to find the source-response relation in order to control other emerging contaminants in a complicated environmental multimedia site.