Evaluating waste management strategies—A case of metal-contaminated waste wood

In Sweden recovered waste wood (RWW) is used for heat production, which reduces the share of waste that is landfilled and recovers the energy content of the waste. However, this waste contains contaminated materials that pollute RWW with heavy metals, causing downstream environmental problems. The main objective of this study was to analyse how different upstream-oriented strategies to manage RWW, influence the arising of environmental pressures downstream the waste management system. Today, the contaminated materials in RWW are handled together with the main waste flow. This upstream approach was compared with a separation strategy that removes contaminants from the main waste flow thereby handling these materials separately downstream the waste management system. An extended substance flow analysis (SFA) methodology that also includes resource issues was applied for the analysis. The results show that the upstream separation strategy exhibits potential environmental benefits. However, to accurately prevent environmental pollution also in a long time perspective, upstream separation strategies must be combined with downstream measures aimed to immobilise the contaminants in by-products. Otherwise, such separation strategies, as the current handling of RWW, may cause temporal and spatial shifting of problems. To enable immobilising measures, however, upstream separation strategies are important since they decrease the volume problem.