Retrofitting a saturated zone (RSAZ) in stormwater biofilters: Impact on pollutants removal

Abstract

Elevated nitrogen levels are one of the main triggers for eutrophication of receiving water bodies. While efficient nitrification occurs in freely drained stormwater biofilters, denitrification is often lacking, which has been identified as the main reason for insufficient N removal or leaching. Furthermore, it has been previously shown that the choice of plant species may influence N removal, with some species potentially resulting in a net leaching, particularly when the filter media itself has relatively high levels of nitrogen. Thus, retrofitting of a submerged zone (SAZ) into poorly performing N removal biofilter might enhance anaerobic conditions for sufficient denitrification. The pri..