Abstract

Since 1990, over 13 000 ha of constructed wetlands (CWs) have been implemented to increase biodiversity and reduce nitrogen (N) and phosphorus (P) loads to Swedish waters. Despite the considerable number of CWs and ambitious investments planned for the coming three years, there is limited follow up of cost-efficiency of catchment- and landscape-scale nutrient retention by existing CWs. Such follow up evaluation could provide clear guidance regarding optimal size and location of future CWs. We present a three-step modelling approach to assess cost-efficiency of 233 CWs in two Swedish regions (East, 4321 km2, and West, 916 km2). Modelled nutrient retention in CWs was predominantly low, especially in the East, due to their suboptimal location in catchments, e.g., with inadequate upstream areas (low hydraulic loads) and/or low share of arable land (low nutrient loads). Suboptimal location of CWs generates both higher than necessary costs and low area-specific nutrient retention, leading to low cost-efficiency. Some high cost-efficiency CWs were identified, especially for N retention in the West. To increase their cost-efficiency, continued investments in CWs require clear guidance and instructions. To achieve optimal placement, both CW site and size in relation to incoming hydraulic and nutrient loads must be considered.

Keywords

Constructed wetlands; Nitrogen; Phosphorus; Modelling; Cost effectiveness

Published in

Journal of Environmental Management
2022, Volume: 324, article number: 116325
Publisher: ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD

SLU Authors

• Djodjic, Faruk

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Geranmayeh, Pia

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Collentine, Dennis

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Markensten, Hampus

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Futter, Martyn

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss


UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use


Publication identifier

DOI: https://doi.org/10.1016/j.jenvman.2022.116325

Permanent link to this page (URI)

https://res.slu.se/id/publ/119893