PIs: Jos Schippers and Joost van Dongen
Runoff from roads and highways is highly polluted and therefore is collected in concrete stormwater retention tanks. Although these tanks efficiently retain most pollutions, like for instance oil, they fail to sediment very fine particles. To solve this problem we aim at using Floating Treatment Wetlands (FTWs), as the biofilm formed around the plant roots is able to successfully retain very fine particles like heavy metals. Importantly, the use of FTWs in the retention tanks brings several major challenges for plant growth. First of all, standstills between rain events results in a severe drop in the oxygen levels in the retention tank, especially in the deeper zones (up to 2.5 m). Secondly, we aim at selecting plants that can deal with the level of contamination present in the highway runoff. Thirdly, during the winter months, the de-incing salts will accumulate in the retention tanks causing a severe salt stress for the plants on the FTWs. The aim of our project is to identifiy NRW-native plants that manage to build a fine root-network to support the formation of the biofilm in the retention tanks and thereby removing pollutants from the flowthrough water.