Innovativa Regnbäddar för hållbar och effektiv rening av urbant dagvatten förorenat med mikroplaster, organiska miljögifter och metaller

Only a few percent of the stormwater generated in urban environments is treated, and therefore transported untreated to nearby watercourses, and the largest proportion of microplastics found in Swedish urban stormwater derives from tires and road wear.

Protecting the environment from the cocktail of pollutants found in stormwater in the form of microplastics, toxic metals and organic pollutants (OP) is of high societal value and a requirement to meet environmental goals.

The aim of this project is to develop innovative rain gardens and to study their efficiency in treating stormwater from the cocktail of pollutants.

It is also to study if and how the accumulated pollutants are degraded, and whether the metals can be used as a resource.

A pilot test raingarden is designed, and experiments are carried out to study beds with bio-charcoal, peat and ash and plants in symbiosis with mycorrhizae fungi including removal efficiency, hydraulic performance, treatment and degradation processes. The pilot will be supplemented with laboratory studies.

The goal is also to identify a sustainable, efficient and innovative method for degradation of microplastics and OP that at the same time recover metals from the materials used in the rain gardens.

The method could also be applicable to contaminated soil and other media such as marine sediments that need to be treated before the materials can be reused. The project contributes to the development of green infrastructure in urban environments.