"The purpose of the study was to investigate how the treatment in a stormwater biofilter is affected by the factors gross pollutant trap, calcium carbonate in the filter material and vegetation on the biofilter. The study compared the concentrations of heavy metals, phosphorus and suspended matter on incoming and outgoing water.
The results showed that the main purification took place inside the biofilter and the gross pollutant trap was most effective for the treatment of dissolved metals. Calcium carbonate as an additive in the filter material had positive effects on the treatment of total and dissolved metals as well as phosphate. Vegetation on the biofilter showed increased treatment of total metals, but released more phosphorus than it removed.
The study was carried out in collaboration with the Urban Water Engineering research group at Luleå University of Technology and the utility company MittSverige Vatten & Avfall, within the framework of Stormwater&Sewers as well as DRIZZLE, funded by Formas and Vinnova. Godecke Blecken has been the supervisor for the work and Maria Viklander the examiner.