Constructed wetlands for tertiary treatment
Constructed wetlands are usually adopted as nature-based solutions for tertiary treatment of centralised activated sludge WWTPs, for instance, due to either an increase of served town or more stringer water quality standard for discharge. Particularly, constructed wetlands are used for tertiary treatments to either provide denitrification or guarantee the effluent wastewater quality standard under variable peak influent loads. They are also used to exploit additional ecosystem services, such biodiversity increase and recreation of areas with a high naturalistic value.
Tertiary treatment - IRIDRA's solutions
Classical constructed wetlands
- Constructed wetlands with horizontal subsurface flow (HF)
- Constructed wetlands with free water surface (FWS)
- Hybrid constructed wetlands (HF + FWS)
Intensified constructed wetlands (Constructed wetlands 2.0)
- Aerated constructed wetlands (FBA™)
Integrated additional solutions
- Wetland restoration
Constructed wetland for tertiary treatment
Several application of constructed wetland for tertiary treatment are known worldwide. For instance, UK counts more than 200 applications in this field. The most representative Italian case is the tertiary treatment of Fusina WWTP: a free water surface system of 100 hectars, treating 4000 m3/h and fully integrated in the Venice lagoon. Another relevant Italian example is the tertiary stage of Jesi WWTP (60,000 PE), designed by IRIDRA: the system is composed by a sedimentation basin, an horizontal subsurface flow systems (10,000 m2) and a free water surface system (50,000 m2), aimed to improve the denitrification and the pathogen removal of the WWPT (Masi, 2008).
Tertiary constructed wetland of the Jesi WWTP (60.000 AE), designed by IRIDRA
Tertiary treatment of Jesi WWTP (AN - Italy)
Treated person equivalent : 60.000 PE
Chosen Nature-based solution : HF + FWS
Year of realization : 2002
Tertiary treatment of Acerra WWTP (NA - Italy)
Treated wastewater quantity : 3000 m3/day
Chosen Nature-based solution : FWS
Peculiarità : Demonstration plant with high naturalistic value. To this aim, up to 13 different plant species were designed to be placed (e.g. Iris pseudacorus, Carex spp, Lythrum salicaria, Botumus umbellatus)
Year of design : 2014
Tertiary treatment of WWTP serving a camping in Chiarore-Graticcia, Capalbio (GR - Italy)
Treated person equivalent : 1200 PE
Chosen Nature-based solution : HF
Year of realization : 2014
Tertiary treatment of Caraglio WWTP (CN - Italy)
Treated person equivalent : 7000 PE
Chosen Nature-based solution : FWS
Year of design : 2016
Tertiary treatment of Trigolo WWTP (CR - Italy)
Treated person equivalent : 1900 PE
Chosen Nature-based solution : FWS
Year of design : 2010
Tertiary treatment of San Casciano dei Bagni WWTP (SI - Italy)
Treated person equivalent : 2000 PE
Chosen Nature-based solution : HF
Year of realization : 2005
Tertiary treatment of Volongo WWTP (CR - Italy)
Treated person equivalent : 1000 a.e.
Chosen Nature-based solution : HF
Year of design : 2012
