Optimization of Municipal Waste Streams in Achieving Urban Circularity in the City of Curitiba, Brazil

Abstract

The municipal solid waste (MSW) remains a great challenge in most cities of developing countries, as the majority of the generated waste is either not collected or is dumped in open uncontrolled non-engineered landfill sites, creating significant pollution due to the leakage of landfill leachate in the surrounding environment. In developing countries, a complete transition to a zero-landfill scenario is less likely to happen in the near future due to various socio-economic challenges. Therefore, the existing landfills in developing countries need holistic waste management thinking with more efforts on waste to energy conversions. This study highlights the challenges with existing MSW management practices of Curitiba, Brazil, and suggests some holistic and sustainable landfill management techniques. This is accomplished through the (i) identification of the suitable sites for setting up transfer stations (TSs), (ii) route optimization for MSW transportation, and (iii) analysis of the life expectancy of the existing landfill with waste valorization techniques for enhancing circularity of MSW of the city. The study has identified six potential TSs, making use of various geological criteria and constraints as suggested by the United States Environmental Protection Agency using GIS-based spatial analysis, which could save fuel cost of approximately 1.5 million Brazilian Real (BRL) per year for the solid waste transportation (from the source to the landfill site). This research has also made a value addition in this specific field with the preparation of a digitized road network map of the study region. Further, the sensitivity-based scenario analysis highlights that the lifespan of the existing landfill (until 2030) might be extended to 2058 if the city achieves the targeted recycling rate of 85% compared with the current rate of 23%. The results would be useful for policy-makers to adopt the crucial MSW scenario to achieve a circular economy in the waste management of the city of Curitiba.