VÅTMARK OXELÖSUND – FULLSKALEFÖRSÖK MED KVÄVERENING I ANLAGDAVÅTMARKER / Wetland Oxelösund – A Full Scale Experiment with Nitrogen Removal in Created Wetlands
A wetland area, including 22 ha of shallow ponds, channels and Inundated fenlands, has been created during 1993 adjacent to the town of Oxelösund (12500 inhabitants) on the Baltic coast of Sweden. The primary goal with the wetland is an annual removal of 22 tonnes of nitrogen from pretreated wastewater from the towns treatment plant. If this goal can be met, the plant will be able to meet the requirement for 50 % reduction of the Incoming nitrogen load. Besides reduction of nitrogen, the wetland will also clean the wastewater from other pollutants. Thus, the wetland can improve the treatment results also for BOD and phosphorus. As the wetland occupy quite a lot of land, an ambition has been to make the wetland both an interesting recreation site for the residents as well as a valuable habitat for wildlife. The annual cost for nitrogen removal in the wetland has been estimated to 50 SEK ($ 6,50) per kg of nitrogen, or one fourth of the estimated cost for conventional nitrification-denitrification treatment. “Complete abstract not presented.”