Life cycle assessment and residue leaching: The importance of parameter, scenario and leaching data selection. (April 2015)

• Record Type: Journal Article
• Authors: Allegrini, E.; Butera, S.; Kosson, D.S.; Van Zomeren, A.; Van der Sloot, H.A.; Astrup, T.F.
• Is Part Of: Waste management. Volume 38(2015)
• Page Start: 474
• Page End: 485
• Publication Date: 2015-04
• Subjects: BA bottom ash -- CF characterisation factor -- CPR construction products regulation -- CTUe comparative toxic unit for ecotoxicity -- CTUh comparative toxic unit for human toxicity -- DOC dissolved organic carbon -- ET ecotoxicity -- FU functional unit -- HTc carcinogenic human toxicity -- HTnc non carcinogenic human toxicity -- LCA life cycle assessment -- LCI life cycle inventory -- LCIA life cycle impact assessment -- L/S liquid-to-solid ratio -- MSW municipal solid waste -- MSWI municipal solid waste incineration -- TC transfer coefficient -- WMS waste management system -- WtE waste-to-energy; Leaching -- Residues -- LCA -- MSWI -- Bottom ash -- Toxic impact; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2014.12.018
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: Relevance of metal leaching in waste management system LCAs was assessed. Toxic impacts from leaching could not be disregarded. Uncertainty of toxicity, due to background activities, determines LCA outcomes. Parameters such as pH and L/S affect LCA results. Data modelling consistency and coverage within an LCA are crucial. Abstract: Residues from industrial processes and waste management systems (WMSs) have been increasingly reutilised, leading to landfilling rate reductions and the optimisation of mineral resource utilisation in society. Life cycle assessment (LCA) is a holistic methodology allowing for the analysis of systems and products and can be applied to waste management systems to identify environmental benefits and critical aspects thereof. From an LCA perspective, residue utilisation provides benefits such as avoiding the production and depletion of primary materials, but it can lead to environmental burdens, due to the potential leaching of toxic substances. In waste LCA studies where residue utilisation is included, leaching has generally been neglected. In this study, municipal solid waste incineration bottom ash (MSWI BA) was used as a case study into three LCA scenarios having different system boundaries. The importance of data quality and parameter selection in the overall LCA results was evaluated, and an innovative method to assess metal transport into the environment was applied, in order to determine emissions to the soil and water compartments for use in an LCA. It was found that toxic impacts as a result of leaching were dominant in systems including only MSWI BA utilisation, while leaching appeared negligible in larger scenarios including the entire waste system. However, leaching could not be disregarded a priori, due to large uncertainties characterising other activities in the scenario (e.g. electricity production). Based on the analysis of relevant parameters relative to leaching, and on general results of the study, recommendations are provided regarding the use of leaching data in LCA studies.