Implementing mechanical biological treatment in an emerging waste management system predominated by waste pickers: A Brazilian case study

Mechanical Biological Treatment (MBT) could be a decisive game-changer for the development of household solid waste management (e.g., reduce waste in landfills). However, in a nascent household waste management (HSWM) system, which is characterized by divergent interest groups ranging from the national government, municipalities, waste pickers and householders as providers of waste, implementing MBTs could create positive but also adverse impacts, in particular on waste pickers (WPs). Formal WPs are in cities, like Belo Horizonte (Brazil), a constituent part of the HSWM. This study builds strategies as a form of normative scenarios to assist decision-making processes to deal with WPs and implement MBTs systems. The present study includes material and energy flows, life cycle environmental impacts and social indicators characterized by the number of active WPs and capacity building. The results show that an integrated commitment of the local society can reduce landfilling by 70% and global warming emissions to a quarter. An emphasis on greenhouse gas emissions, like Belo Horizonte's promise for long-term attitude, brings a broad commitment to developing HSWM since a functioning system based on focused strategies will consequently reflect a positive action on climate. Waste pickers can fulfill the estimated vacancies at MBT plants and promote their active life or not according to the capacity building. MBT has substantial room to grow. Therefore, this growth will only happen with new thoughts on the adaptability of MBT systems focused on sufficiency to secure fair conditions for local livelihoods and targets with systemic implications.