Contact person: Dr Tapio Salo, MTT Agrifood Research

Calcium-iron oxide buffer in Jokioinen, the first test site with boosted phosphate removal in the Active Wetlands project. Water from a small wetland
is led through a granule mass that retains phosphate from the water.
Construction work at the project’s second calcium-iron oxide buffer
by the Lake Rehtijärvi, Jokioinen. Water comes from a horse stable area,
and is further led to a small wetland at the lake shore.
Ferric sulphate doser in a ditch in Jokioinen. The iron chemical dissolves
from a nylon netting cone, in adjustable rate according to the flow conditions, and precipitates phosphate from water in insoluble form.
Estonian and Finnish farmers, rural advisors and decisionmakers will learn more about how wetlands can be used
to reduce the nutrient load from agriculture in the Active
Wetlands -project. Simple and environmentally friendly
methods will be introduced to increase nutrient retention
ability of agricultural wetlands.
Agriculture is the largest anthropogenic source of nutrients ­
(N and P) enhancing eutrophication of the Baltic Sea. Constructed wetlands are recognized as a powerful tool to reduce nutrient
run-off from arable land to the sea. Large and thus efficient wetlands are still rare due to their high investment costs.
Active Wetlands –project is testing methods how to increase
nutrient retention efficiency in small pilot wetlands. These
methods include chemical precipitation with iron compound
as well as the active improvement of vegetation of the wetlands.
Contact person: Dr Tapio Salo, MTT Agrifood Research Finland
Photos: WWF/Sampsa Vilhunen
Partners of the project are: MTT Agrifood Research Finland, Joki­
oinen; Finnish Environment Institute (SYKE); Research Department/ Research Programme for Integrated River Basin Management, Helsinki, Finland; WWF Finland; Turku University of
Applied Sciences (TUAS); Estonian University of Life Sciences,
Institute of Forestry and Rural Engineering, Department of
Water Management and Estonian Fund for Nature (ELF).