Constructed wetlands for nutrient removal
Constructed wetlands are recognized as valuable nature-based solutions for the reduction nutrient discharge in water bodies at eutrophication risk, such as lakes and coastal lagoons. For instance, constructed wetlands were satisfactorily applied to reduce the nutrient loads conveyed by agricultural drainage channels, which are driven by agricultural runoff.
Nutrient removal - IRIDRA's solutions
Classical constructed wetlands
- Constructed wetlands with free water surface (FWS)
Intensified constructed wetlands (Constructed wetlands 2.0)
- Aerated constructed wetlands (FBA™)
Additional integrated solutions
- Combination with additional ecosystem services
- Combination with landscaping solutions for water, green, and cities
- Combination with river restoration solutions
IRIDRA's experience
Several intervents were designed by Consorzio di Bonifica Acque Risorgive to reduce the floods events and the nutrient loads discharged in the Venice lagoon. Among them, IRIDRA has designed in collaboration with ETATEC two free water surface systems of 1.6 and 2.2 hectares, sited inside multi-purpose detention basins. Except for the flood protection, the wetlands are designed to remove 1.1 and 3.9 tonnes of nitrogen per year, function of different management procedures (i.e. with or without harvesting).
Free water surface wetland system for removal of nutrient conveyed by the irrigation network managed by Consorzio di Bonifica Acque Risorgive, designed by IRIDRA
Detention basin of Cento (FE)
River flow treated during not rainy period: 50 l/s
Chosen Nature-Based solution: FWS sited inside the detention basion
Peculiarity: Multipurpose nature-based solution integrating different ecosystem services within the detention basin of Cento additional to flood mitigation: river water quality improvement, recreational site, and biodiversity increase.
Year of design: 2011
River maintenance authority Acque Risorgive, Vernise channel in the municipality of Zero, Branco and Scorzé (VE - Italy)
Channel flow treated during not rainy period: 50 l/s
Chosen Nature-Based solution: FWS
Peculiarity: Intervention included within the plan for restoration of Venice Lagoon
Year of design: 2014
River maintenance authority Acque Risorgive, Dese Sile (VE - Italy)
Channel flow treated during not rainy period: 50 l/s
Chosen Nature-Based solution: FWS
Peculiarity: Multipurpose nature-based solution, aimed to reduce nutrient loads for eutrophication control and weland restoration of high naturalistic value
Year of design: 2015
River maintenance authority Acque Risorgive, Zermason (VE - Italy)
Channel flow treated during not rainy period: 50 l/s
Chosen Nature-Based solution: FWS
Peculiarity: Multipurpose nature-based solution, aimed to reduce nutrient loads for eutrophication control and weland restoration of high naturalistic value
Year of design: 2015
