Constructed wetlands

The Alhagen wetland Photo Lars Nilsson, Nynœshamns kommun

SwedEnviro designs and participates in the construction of extensive wetlands for wastewater and stormwater treatment. Our vision is to combine cost-effective water treatment with the creation of recreational areas and habitats for wildlife.

Some references:

The Oxelösund wetland was constructed in 1993 and was the first full-scale wetland for nitrogen removal in pretreated municipal wastewater in Scandinavia. The results from Oxelösund show that wetland technology can be used as a cost-effective method for nitrogen removal. Water Revival Systems designed the wetland and is today responsible for the management and maintenance of the municipal treatment facility in Oxelösund, including pumping stations, treatment plant, and wetland.

The Alhagen wetland in Nynäshamn removes nitrogen in pretreated municipal wastewater from 16 000 inhabitants in Nynœshamn and Ösmo. The wetland was taken into operation in 1998 and covers 35 hectares. WRS designed the wetland and has also been involved in the implementation. Wetland Alhagen is maybe the most sophisticated constructed wetland for wastewater treatment in Sweden.

In the village of Vadsbro, in the municipality of Flen, WRS is upgrading a small and obsolete wastewater plant. Here, wastewater from 150 people will be treated in a biofilter ditch system after pretreatment by sedimentation, anaerobic filtering, and aerobic treatment in a trickling filter. The sediments from the biofilter ditch, with its adsorbed phosphorus, will be frequently removed and used as fertilizer. This will result in a sustainable nutrient removal and reuse. The new treatment facility including the biofilter ditch system costs half the price of a new package treatment plant and will use 20% as much energy and no chemicals.