Temporal evolution of the environmental performance of implementing selective collection in municipal waste...

The aim of this study is to analyse the evolution of the municipal solid waste management system of João Pessoa (Brazil), which was one of the Brazilian pioneers cities in implementing door-to-door selective collection programmes, in order to analyse the effect of policy decisions adopted in last decade with regard to selective collection. To do it, this study focuses on analysing the evolution, from 2005 to 2015, of the environmental performance of the municipal solid waste management (MSWM) system implemented in different sorting units with selective collection programmes by applying the Life Cycle Assessment (LCA) methodology and using as a starting point data collected directly from the different stakeholders involved in the MSWM system. This article presents the temporal evolution of environmental indicators measuring the environmental performance of the MSWM system implemented in João Pessoa by sorting unit, for each stage of the life cycle of the waste (collection, classification, intermediate transports, recycling and landfilling), for each waste fraction and for each collection method (selective collection or mixed collection), with the aim of identifying the key aspects with the greatest environmental impact and their causes. Results show on one hand, that environmental behaviour of waste management in a door-to-door selective collection programme significantly improves the behaviour of the overall waste management system. Consequently, the potential to reduce the existing environmental impact based on citizens' increased participation in selective collection is evidenced, so the implementation of awareness-raising campaigns should be one of the main issues of the next policies on solid waste. On the other hand, increasing the amount of recyclable wastes collected selectively, implementing alternative methods for valorising the organic fraction (compost/biomethanization) and improving the efficiency of the transportation stage by means of optimizing vehicles or routes, are essential actions to reduce the overall net environmental impact generated by the MSWM system.