title: Environmental impact of rejected materials generated in organic fraction of municipal solid waste anaerobic digestion plants: Comparison of wet and dry process layout.
abstract: Anaerobic digestion of source separated organic fraction of municipal solid waste is an increasing waste valorization alternative instead of incineration or landfilling of untreated biodegradable wastes. Nevertheless, a significant portion of biodegradable wastes entering the plant is lost in pre-treatments and post-treatments of anaerobic digestion facilities together with other improper materials such as plastics, paper, textile materials and metals. The rejected materials lost in these stages have two main implications: (i) less organic material enters to digesters and, as a consequence, there is a loss of biogas production and (ii) the rejected materials end up in landfills or incinerators contributing to environmental impacts such as global warming or eutrophication. The main goals of this study are (i) to estimate potential losses of biogas in the rejected solid materials generated during the pre- and post-treatments of two full-scale anaerobic digestion facilities and (ii) to evaluate the environmental burdens associated to the final disposal (landfill or incineration) of these rejected materials by means of Life Cycle Assessment. This study shows that there is a lost of potential biogas production, ranging from 8% to 15%, due to the loss of organic matter during pre-treatment stages in anaerobic digestion facilities. From an environmental point of view, the Life Cycle Assessment shows that the incineration scenario is the most favorable alternative for eight out of nine impact categories compared with the landfill scenario. The studied impact categories are Climate Change, Fossil depletion, Freshwater eutrophication, Marine eutrophication, Ozone depletion, Particulate matter formation, Photochemical oxidant formation, Terrestrial acidification and Water depletion.
authors.affiliation: Composting Research Group (GICOM), Department of Chemical Engineering, Universitat Autònoma de Barcelona (UAB), 08193 Edifici Q Bellaterra, Barcelona, Spain.
authors.forename: Ana-Belén
authors.initials: AB
authors.lastname: Colazo
authors.affiliation: Composting Research Group (GICOM), Department of Chemical Engineering, Universitat Autònoma de Barcelona (UAB), 08193 Edifici Q Bellaterra, Barcelona, Spain.
authors.forename: Antoni
authors.initials: A
authors.lastname: Sánchez
authors.affiliation: Composting Research Group (GICOM), Department of Chemical Engineering, Universitat Autònoma de Barcelona (UAB), 08193 Edifici Q Bellaterra, Barcelona, Spain. Electronic address: xavier.font@uab.cat.
authors.forename: Xavier
authors.initials: X
authors.lastname: Font
authors.affiliation: Composting Research Group (GICOM), Department of Chemical Engineering, Universitat Autònoma de Barcelona (UAB), 08193 Edifici Q Bellaterra, Barcelona, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Colón
mesh_terms: D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D056804:Biofuels; D002244:Carbon / Q000737:chemistry; D057231:Climate Change; D004560:Electricity; D004784:Environmental Monitoring / Q000379:methods*; D006358:Hot Temperature; D017745:Incineration; D007700:Kinetics; D008697:Methane; D012037:Refuse Disposal / Q000379:methods*; D062611:Solid Waste / Q000032:analysis; D013030:Spain; D064091:Waste Disposal Facilities; D018505:Waste Management / Q000379:methods*
chemical_list: D056804:Biofuels; D062611:Solid Waste; D002244:Carbon; D008697:Methane
keywords: Anaerobic digestion; Biogas; LCA; Landfill; MBT; Organic Fraction of Municipal; Refuses