Assessing the impact of micropollutant mitigation measures using vertical flow constructed wetlands for municipal wastewater catchments in the greater region: a reference case for rural areas

Abstract

The present research aims at giving an approach to the issue of surface water contamination due to micropollutants in rural areas. The catchment of the Sûre river was selected as a reference case for the Greater Region, characterized mainly by settlements with low population density, small water bodies and small- to medium-sized wastewater treatment plants (WWTPs). For these WWTPs, conventional technical solutions for micropollutant elimination are not suitable; therefore, an adapted mitigation strategy is needed to prevent the impact of micropollutants, especially during the dry season. As a suitable alternative to more intensive technologies, Constructed Wetlands (CW) in Vertical Flow (VF) configuration have been successfully tested over a 1-year period and the elimination rate of 27 micropollutants was quantified. Emission reduction by VF was then considered in a static mass balance model that calculates the longitudinal concentration profile for the entire river catchment. The EmiSûre approach, which focuses on river quality (concentrations of pollutants) instead of emitted loads, effectively allowed simulation of adopted measures a priori and resulted in efficient support for decision-makers with WWTP upgrade scenarios. HIGHLIGHTS A novel approach is applied to assess mitigation measures for micropollutants elimination in rural areas.; Constructed wetlands are promising for micropollutants elimination.; Emission reductions by Constructed Wetlands are considered in a static mass balance model.; The selection of the WWTPs resulted in a significant load reduction.; The EmiSûre model successfully serves as a valuable tool for decision-makers.;

Keywords

• constructed wetlands
• emission measures
• emisûre model
• micropollutants