Municipal solid waste management assessment in Galicia (NW Spain) throughout a self-sufficiency management indicator
*
[email protected]
Pedro Villanueva-Rey1,2*, Sara González-García1, Gumersindo Feijoo1 and María Teresa Moreira1 1Departament
of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
2Centre
of Environmental and Marine Studies (CESAM), Department of Environment and Planning, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
INTRODUCTION
Municipal solid waste management (MSW) is an issue in some European countries, especially in the Southern ones, where landfills are the main treatment option (e.g. 60% for Spain). The release of Directive 2008/98/EC, a series of commitments regarding MSW management (i.e. prevention, preparing for re-use, recycling, recovery, and disposal) must be accomplished by 2020 or earlier. Galicia (NW Spain) presents three different MSW management systems, namely SOGAMA, Nostian and Lousame. The differences among them lie in the separation in origin, which will determine the following treatment (Table 1). This study is focused on the MSW management in Galicia to evaluate the environmental performance of its MSW treatment systems through a self-sufficiency management indicator for 2009-2020 period, including the new projected treatment facilities and management changes to meet the established goals.
Table 1. Features and improvements projected of the three Galician MSW management systems selected for assessment. MSW SYSTEM SOGAMA
POPULATION COVERED 2,2410,000 inhabitants (83%) from 296 municipalities
COLLECTION SYSTEM
FACILITIES
Four fractions: Light packaging sorting plant – Glass Refuse derived fuel plant – Paper and cardboard Burning plant with energy recovery – Light packaging Landfill sites – Undifferentiated fraction Wastewater treatment plant (WWTP) (UF) plus biodegradable 37 transfer plants fraction Nostian 380,000 Wet-dry (four fractions): Mechanic and biological (composting) inhabitants – Glass treatment plant (14%) from 9 – Paper and cardboard Anaerobic digestion plant with energy municipalities – Biodegradable fraction recovery from biogas – UF plus light packaging Landfill site and WWTP Wet-dry (four fractions): Mechanic and biological (composting) Lousame 81,000 inhabitants (3%) – Glass treatment plant from 9 – Paper and cardboard Landfill site municipalities – Biodegradable fraction – UF plus light packaging Note: undifferentiated fraction is considered as not separated collection (mixed collection)
PROJECTED IMPROVEMENTS FOR 2020 HORIZON Separate collection of biodegradable fraction and new composting facilities New light packaging treatment plant Improvements on current facilities Incineration of refuses from Nostian and Lousame Improvements on current facilities to increase materials recovery Decrease landfilling necessities due to higher refuses rate Improvements on current facilities to increase materials recovery New facilities to treat individually the separate collected biodegradable fraction from mixed collected fraction
MATERIALS AND METHODS The self-sufficiency indicator proposed by Fragkou et al. (2010) was adapted to the Galician waste management systems. Waste treatment facilities were modeled based on Material Flow Accounting (MFA), taking into account the present and projected operational data (e.g. refuses generation, treatment capacity, recovered materials, etc.). Municipal administrative borders determine system boundaries and the material flows (imports/exports) of the municipalities joined to each waste management system (Figure 1). Thus, MSW generation is considered as a product of socio-economic activities within the system (G). This MSW can be either treated inside (Idom) or outside (Iexp) the system, be landfilled (Iland), or used directly as raw materials after separation collection (e.g. glass and paper and cardboard –P&C). System inputs include MSW imports (Iimp) from other systems to be treated inside the system whilst outputs include waste flows sent to treatment in external plants, as well as secondary waste generated in treatment plants (OA – IB) that can be either delivered outside system for further treatment or merely landfilled (OB). Air emissions and wastewater generated during waste treatment processes are not considered for the computation of the outputs. Therefore, the proposed indicator aims at evaluating the capacity in closing materials loops of a given system in a specific time period, so it can be defined as the ratio between recovered materials and the total amount of waste generated in it.
Figure 1. Representation of system limits for indicator computation. Adapted from Fragkou et al. (2010)
RESULTS AND DISCUSSION The self-sufficiency indicator results have shown a tendency towards the unity during the evaluated period (Figure 2). Serious operational problems of the systems explains the moderate figures obtained for 2009-2013 period. SOGAMA system obtained the higher figures whilst Nostian and Lousame systems attained lower values. MSW generation it is expected to decreased by 15% for 2020 horizon due to population losses and prevention campaigns. Mixed collection was reduced significantly (circa 50% regarding 2009 figures) due to the new collection scheme established for biodegradable fraction in SOGAMA system. Landfilling necessities were reduced considerably, from 660,000 t/y to 190,000 t/y for 2009 in 2020 respectively. 50% preparing for re-use or recycling target would be achieved for metals plastics, glass and P&C, recycling up to 52% of these fractions. Additionally, the landfilling goals of 0% for MSW with no prior treatment and 35% for refuses have been updated to 0% and 20%, respectively, by 2020.
CONCLUSIONS Figure 2. Self-sufficiency indicator results and evolution of the MSW fractions collected for the three systems and Galicia as a whole during the 2009-2020 period
Mixed collection and landfilling necessities were reduced considerably due to the new projected facilities and the changes implemented on the MSW management systems. Projected facilities and changes over Galicia MSW treatment systems would allow to meet established goals regarding landfilling and preparing for re-use or recycling. The delivering of refuses from other systems to be burnt in SOGAMA reduces the landfilling
REFERENCES Fragkou, M.C., Vicent, T., Gabarrell, X., 2010. A general methodology for calculating the MSW management self-sufficiency indicator: Application to the wider Barcelona area. Resources, Conservation and Recycling 54, 390–399 Xunta de Galicia, 2011. Plan de xestión de residuos urbanos de Galicia (PXRUG) 2010-2020. Consellería de Medio Ambiente, Territorio e Infraestructuras. Xunta de Galicia, 2014a. Actualización do PXRUG 2010-2020. Consellería de Medio Ambiente, Territorio e Infraestructuras. Xunta de Galicia, 2014b. Instituto Galego de Estatística [WWW Document]. IGE: Instituto Galego de Estatística. URL http://www.ige.eu/web/index.jsp?idioma=gl
ACKNOWLEDGEMENTS This work was financially supported by the Spanish Ministry of Economy and Competitiveness (project ref. CTQ2016-75136-P) and by Xunta de Galicia (project ref. ED431F 2016/001). Dr. S. González-Garcia would like to express her gratitude to the Spanish Ministry of Economy and Competitivity for financial support (Grant reference RYC-2014-14984). Dr. Pedro Villanueva-Rey would like to thank the Galician Government for financial support (I2C postdoctoral student grants programme). The authors belong to the Galician Competitive Research Group GRC 2013-032 as well as to CRETUS (AGRUP2015/02), co-funded by Xunta de Galicia and FEDER.
