基于混合生命周期评价的生活垃圾处理系统生态效率分析

基于混合生命周期评价(Hybrid life cycle assessment,HLCA)提出一种改进生态效率模型,系统评价卫生填埋、卫生填埋⁃填埋气利用、焚烧发电、堆肥+卫生填埋和堆肥+焚烧发电5种我国典型生活垃圾处理情景的生态效率,并探究可持续性包含的环境、经济和社会多维权衡关系。结果表明,具有最大生态效率的生活垃圾处理情景因可持续性维度选取不同而异,如考虑人体健康损害影响,焚烧发电情景具有最大经济生态效率,而卫生填埋⁃填埋气利用情景具有最大社会生态效率。生活垃圾处理系统的可持续性评价维度之间具有显著的权衡关系,忽略某些影响类型可能带来问题转移。5种生活垃圾处理情景的环境影响各异,非焚烧情景气候变化影响和焚烧情景人体毒性影响突出。机器设备和燃料使用对资源消耗影响贡献最大,而生活垃圾处理过程对经济效益和其他环境影响贡献最大。本文提出的改进生态效率模型可以定量评价生活垃圾管理系统生态效率及权衡关系,为有效制定生活垃圾管理政策提供全面的信息支持。

Improved eco-efficiency analysis of municipal solid waste treatment systems based on hybrid life cycle assessment

In this study, an improved eco-efficiency analysis based on the integrated hybrid life cycle assessment method has been proposed. The eco-efficiencies of five typical municipal solid waste (MSW) treatment scenarios, landfilling, landfilling with landfill gas utilization, incineration, composting+landfilling, and composting+incineration, were evaluated using the proposed method. The trade-offs in the sustainability performance of the MSW treatment scenarios were also investigated. The results show that most of the eco-efficient scenarios were different across the sustainability domains. For example, with respect to human health damage, incineration had the highest economic eco-efficiency, and landfilling with landfill gas utilization had the highest social eco-efficiency. Trade-offs in the sustainability performance of the MSW treatment scenarios were obvious, indicating that ignoring certain impacts will induce unintended problem-shifting in MSW management. Five MSW treatment scenarios showed various environmental impact performances. The climate-change impact scores of the non-incineration scenarios and human-toxicity impact scores of the incineration scenarios were predominant. Equipment and machinery use and diesel use dominated the resource depletion impacts in all the scenarios, whereas MSW treatment processes dominated the economic performance and other environmental impacts. The improved eco-efficiency analysis can support sustainable MSW management and provide comprehensive information for improving the effectiveness of MSW management policies in China.