Small-scale Wastewater treatment systems based on filter Innovative Materials (SWIM)

Important results from the project

The overall aim was to focus on developing the right combination of filters and reactive filter media to maximize capture and subsequent recycling of phosphorus while eliminating nitrogen and bacteria effectively. The prototype will consist of a treatment solution that is easier, cheaper and safer to install and maintain than current small-scale sewage plants. The target has been met for phosphorus and bacteria, but nitrogen is still a problem for the type of alkaline filter used in this project.

Expected long term effects

KTH has contributed to the project through mainly work package 2. This has meant that new knowledge was added so that the SWIM solution was designed and developed. A dual-filter with Sorbulite as a premiere to Polonite has been tested. Furthermore, for the first time, Polonite was tested as a polishing step for phosphorus after primary purification in wetlands. The effect is that the sale of the solution has been initiated both in Sweden and Poland. The assessment method for phosphorus absorption and fertilization is recommended for the future. A modeling tool has been developed in Comsol.

Approach and implementation

The project has been initiated with literature review and laboratory trials and the results have been implemented in three SWIM solutions: Söräng, Mörkö; package wastewater treatment plant with Polonite at the test site Ilawa, Poland; constructed wetland with Polonite at the test site Ilawa. Poland. Technical disturbances (climate-related) meant that the length of the test period was considerably shorter than planned. Important experience has been gained that can both improve system solution but also widen the applications. The materials studied met the expectations.