Sustainability of Waste Management System: Treatment and Separation for Material Recovery

Abstract

Increased global concern on the state of our climate has driven also the waste management sector to look for solutions that enable lowering of the environmental impacts by increasing waste reduction and material recycling. Material recycling is more feasible and efficient when there is source separation in place because source separation usually leads to the best quality of the separated materials. However, sometimes source separation does not work properly (e.g., because of the low education level of people) or it is difficult to apply (e.g., because of a fixed and dense city infrastructure). The strict material recycling targets in the EU necessity that mechanical separation is included as a tool for increasing the recycling rate. The aim of the mechanical treatment is to separate materials suitable for recycling from the mixed waste stream by separating recoverable components and impurities to different streams. A multitude of processes is usually required to obtain recyclable materials out of the mixed waste stream, for example, from mixed municipal solid waste (MSW) or mixed construction and demolition waste (C&D waste). However, it should be borne in mind that often the most important factors from the environmental impacts point of view for recovery of materials by mechanical treatment are yield of recoverables, quality and demand of recovered materials as well as the environmental impact of replaced virgin materials. At the end of the day, the tightened recycling rates strive for the development of various treatment and separation technologies and their better performance is achieved.