title: Beyond the conventional life cycle inventory in wastewater treatment plants.
abstract: The conventional approach for the environmental assessment of wastewater treatment plants (WWTPs) is typically based on the removal efficiency of organic load and nutrients as well as the quantification of energy and chemicals consumption. Current wastewater treatment research entails the monitoring of direct emissions of greenhouse gases (GHG) and emerging pollutants such as pharmaceutical and personal care products (PPCPs), which have been rarely considered in the environmental assessment of a wastewater treatment facility by life cycle assessment (LCA) methodology. As a result of that, the real environmental impacts of a WWTP may be underestimated. In this study, two WWTPs located in different climatic regions (Atlantic and Mediterranean) of Spain were evaluated in extensive sampling campaigns that included not only conventional water quality parameters but also direct GHG emissions and PPCPs in water and sludge lines. Regarding the GHG monitoring campaign, on-site measurements of methane (CH4) and nitrous oxide (N2O) were performed and emission factors were calculated for both WWTPs. GHG direct emissions accounted for 62% of the total global warming potential (GWP), much more relevant than indirect CO2 emissions associated with electricity use. Regarding PPCPs, 19 compounds were measured in the main streams: influent, effluent and sludge, to perform the evaluation of the toxicity impact categories. Although the presence of heavy metals in the effluent and the sludge as well as the toxicity linked to the electricity production may shade the toxicity impacts linked to PPCPs in some impact categories, the latter showed a notable influence on freshwater ecotoxicity potential (FETP). For this impact category, the removal of PPCPs within the wastewater treatment was remarkably important and arose as an environmental benefit in comparison with the non-treatment scenario.
authors.affiliation: Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain. Electronic address: yago.lorenzo@usc.es.
authors.forename: Yago
authors.initials: Y
authors.lastname: Lorenzo-Toja
authors.affiliation: Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Alfonsín
authors.affiliation: Cetaqua, Water Technology Centre, 08940 Cornellà de Llobregat, Barcelona, Spain.
authors.forename: María José
authors.initials: MJ
authors.lastname: Amores
authors.affiliation: Cetaqua, Water Technology Centre, 08940 Cornellà de Llobregat, Barcelona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Aldea
authors.affiliation: Cetaqua, Water Technology Centre, 08940 Cornellà de Llobregat, Barcelona, Spain.
authors.forename: Desirée
authors.initials: D
authors.lastname: Marin
authors.affiliation: Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain.
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Moreira
authors.affiliation: Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela, Galicia, Spain.
authors.forename: Gumersindo
authors.initials: G
authors.lastname: Feijoo
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D008697:Methane; D009609:Nitrous Oxide; D018570:Risk Assessment; D013030:Spain; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000706:statistics & numerical data*
chemical_list: D008697:Methane; D009609:Nitrous Oxide; D062065:Wastewater
keywords: Greenhouse gas (GHG) emissions; Life cycle assessment (LCA); Pharmaceutical and personal care products (PPCPs); Wastewater treatment