IES tests a phosphorus filter for reduction of harmful inflows in the Baltic Sea


Eutrophication is a major problem in the Baltic Sea. It is caused by the nutrient inflows coming from human activities. Phosphorus is widely used as a fertilizer to increase agricultural crop yields. The biggest rivers bring 20 000 tons of phosphorus in the Baltic sea each year, which leads to heavy algal blooms.

To reduce nutrient and harmful inflows in the Baltic Sea, in the Summer of 2018, the Institute for Environmental Solutions in cooperation with Tallinn University of Technology has tested special environmental technology – phosphorus filter on pilot watersheds in Latvia and in laboratory in Estonia. See the testing process in the video below:



The filter was installed in a drainage ditch located in the municipality of Ogre, Latvia. After few weeks the filter got clogged and water flow stopped. To examine this problem in detail, researchers built a scaled down model filter in the Laboratory of Fluid Mechanics at the Tallinn University of Technology. The results of tests will be used to make further decisions of constructing similar filtering technologies.

The filter testing is a part of the project “Pilot watersheds as a practical tool to reduce the harmful inflows into the Baltic Sea” (WATERCHAIN) No.CB50, which is co-funded by ERDF Central Baltic Interreg IV Programme 2014 – 2020.

Find out more about the WATERCHAIN project here.