title: Should we pretreat solid waste prior to anaerobic digestion? An assessment of its environmental cost.
abstract: Many studies have shown the effectiveness of pretreatments prior to anaerobic digestion of solid wastes, but to our knowledge, none analyzes their environmental consequences/costs. In this work, seven different pretreatments applied to two types of waste (kitchen waste and sewage sludge) have been environmentally evaluated by using life cycle assessment (LCA) methodology. The results show that the environmental burdens associated to the application of pretreatments prior to anaerobic digestion cannot be excluded. Among the options tested, the pressurize-depressurize and chemical (acid or alkaline) pretreatments could be recommended on the basis of their beneficial net environmental performance, while thermal and ozonation alternatives require energy efficiency optimization to reduce their environmental burdens. Reconciling operational, economic and environmental aspects in a holistic approach for the selection of the most sustainable option, mechanical (e.g., pressurize-depressurize) and chemical methods appear to be the most appropriate alternatives at this stage.
authors: Department of Chemical Engineering, School of Engineering, University of Santiago de Compostela, Rúa Lope Gómez de Marzoa s/n, E-15782 Santiago de Compostela, Spain. marta.carballa@usc.es
authors: Marta
authors: M
authors: Carballa
authors: Cecilia
authors: C
authors: Duran
authors: Almudena
authors: A
authors: Hospido
mesh_terms: D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D003247:Conservation of Natural Resources; D004777:Environment; D004787:Environmental Pollution / Q000032:analysis / Q000517:prevention & control / Q000706:statistics & numerical data; D005735:Garbage; D012037:Refuse Disposal / Q000191:economics / Q000379:methods*