Sustainability evaluation of e-waste treatment based on emergy analysis and the LCA method: A case study of a trial project in Macau

Electrical and electronic waste (e-waste) has become one of the fastest growing waste streams in the world, and many countries have established e-waste treatment enterprises to solve their e-waste problems. Because of the potential environmental pollution from e-waste, evaluating the overall sustainability of e-waste enterprises is critical to both nations and cities, although a great challenge academically. In this study, a combined approach of emergy analysis and life cycle assessment (LCA) was undertaken, to quantitatively investigate the effectiveness of an e-waste treatment trial project in Macau. In the emergy analysis, we also introduced two new indices (emergy recovery and technical efficiency) in order to evaluate the technical level of e-waste treatment in Macau. The research results show that the trial project has low competitive ability, due to high input emergy and low economic benefits. The emergy environmental efficiency analysis and LCA analysis together indicated that the trial project will indeed produce a low impact on the local environment, and because of the recovery of some resources in the e-waste treatment process, can even generate some environmental benefits. The analysis on the emergy recovery efficiency and technical efficiency shows that trial project has a relatively higher emergy recovery rate (52.78%) and technical level (72.36%) than the e-waste treatment enterprises in mainland China. However, based on both the emergy sustainability index (ESI) and the emergy-LCA sustainability index, it was found that the e-waste treatment trial project is not sustainable over the long term, due to low economic efficiency. Compared to ESI, the emergy-LCA sustainability index is more intuitive and easier to understand. Relevant results and data from this study could provide decision support to enterprise managers and government sectors, so that they could implement appropriate policies on e-waste treatment, to promote sustainable development and improved e-waste processing technologies.