Performance of lagoon and constructed wetland systems for tertiary wastewater treatment and potential of reclaimed water in agricultural irrigation

Giuseppe Mancuso; Stevo Lavrnić; Alba Canet-Martí; Ammad Zaheer; Francesco Avolio; Guenter Langergraber; Attilio Toscano

doi:10.1016/j.jenvman.2023.119278

Performance of lagoon and constructed wetland systems for tertiary wastewater treatment and potential of reclaimed water in agricultural irrigation

J Environ Manage. 2023 Dec 15:348:119278. doi: 10.1016/j.jenvman.2023.119278. Epub 2023 Oct 11.

Authors

Giuseppe Mancuso¹, Stevo Lavrnić², Alba Canet-Martí³, Ammad Zaheer², Francesco Avolio⁴, Guenter Langergraber³, Attilio Toscano²

Affiliations

¹ Alma Mater Studiorum - University of Bologna, Department of Agricultural and Food Sciences, viale Giuseppe Fanin 50, Bologna, 40127, Italy. Electronic address: g.mancuso@unibo.it.
² Alma Mater Studiorum - University of Bologna, Department of Agricultural and Food Sciences, viale Giuseppe Fanin 50, Bologna, 40127, Italy.
³ University of Natural Resources and Life Sciences, Vienna (BOKU), Department of Water Atmosphere and Environment, Institute of Sanitary Engineering and Water Pollution Control, Muthgasse 18, Vienna, 1190, Austria.
⁴ HERA SpA - Water Direction, via Razzaboni 80, Modena, 41122, Italy.

PMID: 37832301
DOI: 10.1016/j.jenvman.2023.119278

Abstract

Climate change poses challenges to agricultural water resources, both in terms of quantity and quality. As an adaptation measure, the new European Regulation (EU) 2020/741 establishes different water quality classes for the use of reclaimed water in agricultural irrigation. Italy is also working on the definition of a new regulation on reclaimed water reuse for agricultural irrigation (in substitution of the current one) that will also include the specific requirements imposed by the European one. Nature-based Solutions (NBS) can be a cost-effective and environmentally friendly way to facilitate water reclamation and reuse. The present study reports the outcomes of a long-term monitoring campaign of two NBS (e.g., a constructed wetland (CW) and a lagoon system (LS)) comparing influent and effluent concentrations of different contaminants (e.g., E. coli, BOD₅, TSS, TN and TP) with the threshold values imposed by the new regulations. The results showed that in both the case studies, E. coli (about 100 CFU 100 mL^-1) and BOD₅ (lower than 25 mg L^-1) mean effluent concentration need to be further reduced in reclaimed water to be suitable for unlimited reuse. As a negative aspect, in both the monitored NBS, an increase in TSS mean concentration in the effluent was observed, up to 40 mg L^-1 in the case of the LS, making reclaimed water unsuitable for agricultural reuse. The CW has proven to be more effective in nitrogen removal (the effluent mean concentration was 3.4 mg L^-1), whereas the LS was better at phosphorus removal (with an effluent mean concentration of 0.4 mg L^-1). Based on the results, recommendations were made to further improve the performance of both systems in order to have adequate water quality, even for class A. Furthermore, the capacity of reclaimed water to meet crop water and nutrient needs was analyzed, and total nitrogen removal rate coefficients were calculated for the design of future LSs.

Keywords: (EU) 2020/741; Agricultural irrigation; Constructed wetlands; Lagoon systems; Wastewater treatment; Water reuse.

MeSH terms

Agricultural Irrigation* / methods
Escherichia coli
Waste Disposal, Fluid / methods
Wastewater
Water Purification*
Wetlands

Substances

Wastewater