Combining multimedia models with integrated urban water system models for micropollutants

摘要

Integrated urban water system (IUWS) modeling aims at assessing the quality of the surfacenwater receiving the urban emissions through sewage treatment plants, combined sewernoverflows (CSOs) and stormwater drainage systems. However, some micropollutants tend tonappear in more than one environmental medium (air, water, sediment, soil, groundwater, etc.).nIn this work, a multimedia fate and transport model (MFTM) is “wrapped around” a dynamic IUWSnmodel for organic micropollutants to enable integrated environmental assessment. The combinednmodel was tested on a hypothetical catchment using two scenarios: on the one hand a referencenscenario with a combined sewerage system and on the other hand a stormwater infiltrationnpond scenario, as an example of a sustainable urban drainage system (SUDS). A case fornBis(2-ethylhexyl) phthalate (DEHP) was simulated and resulted in reduced surface waternconcentrations for the latter scenario. However, the model also showed that this was at thenexpense of increased fluxes to air, groundwater and infiltration pond soil. The latter effects arengenerally not included in IUWS models, whereas MTFMs usually do not consider dynamic surfacenwater concentrations,; hence the combined model approach provides a better basis fornintegrated environmental assessment of micropollutants’ fate in urban environments.