Pilot 4: Constructed wetland system for stormwater - Sweden Water Research

Pilot 4: Constructed wetland system for stormwater

A pilot station was established to verify the efficiency of microplastic removal from urban stormwater. The pilot is an artificial wetland (constructed wetland), using Nature Based Solutions in the form of aquatic plants (common reed) and filtration beds (gravel of suitably selected grain size)

Stormwater from the stormwater collector is directed to the pilot station, that consists of 5 steel tanks (including a multi-stage wetland system) constituting elements of the filtration system through which stormwater supplied to the system gradually flows.

The first tank contains probes that are used to measure basic parameters of water flowing into the station (pH, temperature, oxidation-reduction potential (redox), conductivity, turbidity, and dissolved oxygen). It also plays the role of a sedimentation tank. Two more tanks are filled with a filter bed in which the common reed (Phragmites australis) has been planted. Tank No. 2 is a bed with vertical flow (VF-CW), and Tank No. 3 with horizontal flow (HF-CW). The order of these two tanks can be changed by opening or closing the corresponding valves. After passing through the subsequent filter beds, the water goes to tank No. 4, which acts as a cleaning pond with a variable depth filter bed. The last, fifth tank stores purified water and, like tank No. 1, is equipped with a measuring system.

Read more in the report Piloting technologies for microplastics removal from urban waters