Ongoing work with the REWAISE storm water pilot plant in Sweden

The pilot plant at VA SYDs storm water pond in Lund, Sweden. The sign says, “Here we are doing research within the project REWAISE to find new ways to treat rainwater and reduce the use of drinking water”.

Work has been going on since the summer with the REWAISE stormwater pilot plant in one of VA SYDs storm water ponds in the city of Lund, Sweden. The first samples show that there are microplastics in the pond.

This summer, REWAISE placed a containerized treatment plant at one of VA SYDs storm water ponds in the city of Lund, Sweden. The purpose is to evaluate the capacity of membranes to remove pollutants and report the quality of the stormwater before and after treatment. This is the first step towards designing a space-efficient prototype with membrane cleaning that can be installed in properties

Lund University’s membrane researchers are responsible for the work of optimizing the pilot plant regarding membranes and capacity.

The membranes initially selected are ceramic silicon carbide membranes (Liqtech, Denmark) with a nominal pore size of 0.2 micro and molecular weight cut-off (MWCO) of approximately 400 kDalton. The submerged membrane area of close to 10 m2 is suitable for average stormwater purification capacities of 300 – 1000 l/h, to determine the removal of microplastics and micropollutants.  The membrane unit can be operated with aeration to reduce membrane fouling and the membranes can be cleaned using backflushing as well.

The first microplastic analysis show that there are microplastics in the storm water pond. The Aalborg University in Denmark will, within the FanpLESStic-Sea project, analyze the quantity and type of plastic.

Visit the website ( to learn more about the work VA SYD is developing in the REWAISE stormwater pilot plant. The content is in Swedish at the moment.