Mechanical biological treatments (MBTs) are extensively used for managing municipal solid waste (MSW). There are four different methods: fertilizer or compost-like output production, biogas/energy production, waste-derived fuel production and disposal in landfills. One issue is the varying characteristics of the waste fed over the lifetime of the plant. This problem is only partially related to the composition dynamics of the generated MSW. Indeed, the main source of input fluctuation of the plant is a result of the implementation of selective collection (SC) strategies, which modify the composition of residual MSW (RMSW). Often the SC strategies are not developed in harmony with the presence or planning of treatment plants, which can consequently suffer from significant variations. A lack of optimization in MSW management strategies and the implementation of new more stringent regulations applied to the final solid products from MBTs could result in a higher tariff for the users. This paper analyses these two problems in terms of two SC scenarios. The consequent effects on the composition of RMSW and on the performance of bio-drying (one of the MBTs options) are discussed. The effect of different SC strategies of MSW is analysed also in terms of RMSW suitability to be converted into refuse derived fuel/solid recovered fuel with simplified treatments. The role of respirometry is also discussed.
Biological mechanical treatment, municipal solid waste, refuse derived fuel, respirometry, selective collection, solid recovery fuel
 EC-Directorate-General Environment, Directorate A-Sustainable Development and Policy Support, Working document, Biological treatment of biowaste, 2nd draft, Brussels, 12 February, 2001.
 Donovan, S.M., Bateson, T., Gronow, J.R. & Voulvoulis, N., Characterization of compostlike outputs from mechanical biological treatment of municipal solid waste. Journal of the Air and Waste Management Association, 60(6), pp. 694–701, 2010. doi: http://dx.doi.org/10.3155/1047-32184.108.40.2064
 Montejo, C., Tonini, D., Márquez, M.D.C. & Fruergaard Astrup, T., Mechanical-biological treatment: performance and potentials. An LCA of 8 MBT plants including waste characterization. Journal of Environmental Management, 128, pp. 661–673, 2013. doi: http://dx.doi.org/10.1016/j.jenvman.2013.05.063
 Ionescu, G., Rada, E.C., Ragazzi, M., Marculescu, C., Badea, A. & Apostol, T., Integrated municipal solid waste scenario model using advanced pretreatment and waste to energy processes. Energy Conservation and Management, 76, pp. 1083–1092, 2013. doi: http://dx.doi.org/10.1016/j.enconman.2013.08.049
 Siddiqui, A.A., Powrie, W. & Richards D.J., Impact of pretreatment on the landfill behaviour of MBT waste. WIT Transactions on Ecology and the Environment, 173, pp. 627–638, 2013. doi: http://dx.doi.org/10.2495/sdp130521
 Rada, E.C., Ragazzi, M. & Apostol, T., Municipal solid waste bio-drying viability in different countries. Proc. of mechanical biological waste treatment and material recovery facilities, Gottingen Cullivier Verlag: Hanover, pp. 565–570, 2009.
 Ragazzi, M. & Rada, E.C., RDF/SRF evolution and MSW bio-drying, Waste Management and the Environment IV, eds., V. Popov, H. Itoch & C.A. Brebbia, Wit Press: Southampton, 163, pp.199–208, 2012. doi: http://dx.doi.org/10.2495/wm120191
 Velis, C.A., Longhurst, P.J., Drew, G.H., Smith, R. & Pollard, S.J.T., Biodrying for mechanical–biological treatment of wastes: a review of process science and engineering. Bioresource Technology, 100(11), pp. 2747–2761, 2009. doi: http://dx.doi.org/10.1016/j.biortech.2008.12.026
 Rada, E.C., Ragazzi, M. & Badea, A., MSW bio-drying: design criteria from a 10 years research. Scientific Bulletin, series D, 74(3), pp. 209–216, 2012.
 Velis, C.A. & Cooper, J., Are solid recovered fuels resource-efficient? Waste Management and Research, 31(2), pp. 113–114, 2013. doi: http://dx.doi.org/10.1177/0734242x13476385
 Velis, C.A., Longhurst, P.J., Drew, G.H., Smith, R. & Pollard, S.J.T., Production and quality assurance of solid recovered fuels using mechanical-biological treatment (MBT) of waste: a comprehensive assessment. Critical Reviews in Environmental Science and Technology, 40(12), pp. 979–1105, 2010. doi: http://dx.doi.org/10.1080/10643380802586980
 Velis, C., Wagland, S., Longhurst, P., Pollard, S., Robson, B. Sinfield, K. & Wise, S., Solid recovered fuel: influence of waste stream composition and processing on chlorine content and fuel quality. Environmental Science and Technology, 46(3), pp. 1923–1931, 2012. doi: http://dx.doi.org/10.1021/es2035653
 Choi, Y.S., Han, S., Choi, H.S. & Kim, S.J., Characterization of Korean solid recovered fuels (SRFs): an analysis and comparison of SRFs. Waste Management and Research, 30(4), pp. 442–449, 2012. doi: http://dx.doi.org/10.1177/0734242x12441239
 Skutan, S. & Brunner, P.H., Metals in RDF and other high calorific value fractions from mechanical treatment of MSW: analysis and sampling errors. Waste Management and Research, 30(7), pp. 645–655, 2012. doi: http://dx.doi.org/10.1177/0734242x12442740
 ERFO-European Recovered Fuel Organisation, SRF: achieving environmental and energyrelated goals market – Workshop Quo Vadis on 22 June 2006 in Larnaca Cyprus, 2006.
 Glorius, T., Production and Use of Solid Recovered Fuels - Developments and Prospects, Berliner Abfallwirtschafts- und Energiekonferenz Berlin 30. - -31.01.2012,
 Rada, E.C. & Andreottola, G. RDF/SRF: which perspective for its future in the EU. Waste Management, 32(6), pp. 1059–1060, 2012. doi: http://dx.doi.org/10.1016/j.wasman.2012.02.017
 Consonni, S., Giugliano, M., Massarutto, A., Ragazzi, M. & Saccani, C., Material and energy recovery in integrated waste management systems: project overview and main results. Waste Management, 31(9–10), pp. 2057–2065, 2011. doi: http://dx.doi.org/10.1016/j.wasman.2011.04.016
 Ragazzi, M. & Rada, E.C., Effects of recent strategies of selective collection on the design of municipal solid waste treatment plants in Italy. WIT Transactions on Ecology and the Environment, eds. M. Zamorano, C.A. Brebbia, A.G. Kungalos, V. Popov & H. Itoh, Wit Press: Southampton, 109, pp. 613–620, 2008.
 CEN/TC 15359:2006 - Solid recovered fuels - Specifications and classes. doi: http://dx.doi.org/10.3403/30141009
 Binner, E., Böhm, K. & Lechner, P., Large scale study on measurement of respiration activity (AT4) by Sapromat and OxiTop. Waste Management, 32(10), pp. 1752–1759, 2012. doi: http://dx.doi.org/10.1016/j.wasman.2012.05.024
 Raicu, S., Costescu, D., Roşca, E. & Popa, M., Optimal planning of selective waste collection. WIT Transactions on Ecology and the Environment, 150, pp. 785–794, 2011. doi: http://dx.doi.org/10.2495/sdp110651
 ANPM (National Agency of Environment Protection), 2009. Report regarding MSW collection, valorification and recycling in 2009 (Romania), http://www.anpm.ro (accessed in 2012).
 Ionescu, G. & Rada, E.C., Material and energy recovery in a municipal solid waste system: practical applicability. International Journal of Environment and Resource, 1(1), pp. 26–30, 2012.
 PAT – Autonomous Province of Trento, Internal data-base, (2012).
 Rada, E.C., Franzinelli, A., Taiss, M., Ragazzi, M., Panaitescu, V. & Apostol, T., Lower heating value dynamics during municipal solid waste bio-drying. Environmental Technology, 28(4), pp. 463–469, 2007. doi: http://dx.doi.org/10.1080/09593332808618807
 Rotter, V.S., Kost, T., Winkler, J. & Bilitewski, B. Material flow analysis of RDF-production processes. Waste Management, 24(10), pp. 1005–1021, 2004. doi: http://dx.doi.org/10.1016/j.wasman.2004.07.015