Politecnico di Milano - DIIAR, Environmental Section, P.zza Leonardo da Vinci 32, 20133 Milano, Italy.
Waste Manag. 2011 Sep-Oct;31(9-10):2092-101. doi: 10.1016/j.wasman.2011.02.029. Epub 2011 Apr 8.
This paper reports the environmental results, integrated with those arising from mass and energy balances, of a research project on the comparative analysis of strategies for material and energy recovery from waste, funded by the Italian Ministry of Education, University and Research. The project, involving the cooperation of five University research groups, was devoted to the optimisation of material and energy recovery activities within integrated municipal solid waste (MSW) management systems. Four scenarios of separate collection (overall value of 35%, 50% without the collection of food waste, 50% including the collection of food waste, 65%) were defined for the implementation of energetic, environmental and economic balances. Two sizes of integrated MSW management system (IWMS) were considered: a metropolitan area, with a gross MSW production of 750,000 t/year and an average province, with a gross MSW production of 150,000 t/year. The environmental analysis was conducted using Life Cycle Assessment methodology (LCA), for both material and energy recovery activities. In order to avoid allocation we have used the technique of the expansion of the system boundaries. This means taking into consideration the impact on the environment related to the waste management activities in comparison with the avoided impacts related to the saving of raw materials and primary energy. Under the hypotheses of the study, both for the large and for the small IWMS, the energetic and environmental benefits are higher than the energetic and environmental impacts for all the scenarios analysed in terms of all the indicators considered: the scenario with 50% separate collection in a drop-off scheme excluding food waste shows the most promising perspectives, mainly arising from the highest collection (and recycling) of all the packaging materials, which is the activity giving the biggest energetic and environmental benefits. Main conclusions of the study in the general field of the assessment of the environmental performance of any integrated waste management scheme address the importance of properly defining, beyond the design value assumed for the separate collection as a whole, also the yields of each material recovered; particular significance is finally related to the amount of residues deriving from material recovery activities, resulting on average in the order of 20% of the collected materials.
本文报告了一个由意大利教育、大学和研究部资助的研究项目的环境成果，该项目综合了物质和能量平衡的成果，该项目涉及五个大学研究小组的合作，致力于优化综合城市固体废物（MSW）管理系统内的物质和能量回收活动。为了实施能量、环境和经济平衡，为能源、环境和经济平衡定义了四个单独收集方案（总价值为 35%，不收集食物废物的 50%，包括食物废物收集的 50%，65%）。考虑了两种大小的综合 MSW 管理系统（IWMS）：一个大都市区，每年产生 750,000 吨垃圾，一个平均省份，每年产生 150,000 吨垃圾。环境分析采用生命周期评估方法（LCA），对物质和能量回收活动进行分析。为了避免分配，我们使用了系统边界扩展技术。这意味着要考虑与废物管理活动相关的环境影响，以及与节约原材料和一次能源相关的避免影响。根据研究的假设，对于大型和小型 IWMS，所有分析方案的所有指标的能量和环境效益都高于能量和环境影响：在不包括食物废物的下拉方案中进行 50%的单独收集的方案显示出最有前途的前景，主要来自于所有包装材料的最高收集（和回收），这是给予最大能量和环境效益的活动。研究在综合废物管理计划环境绩效评估的一般领域的主要结论涉及到除了单独收集的设计值之外，还正确定义每个回收材料的产量的重要性；最后特别重要的是与材料回收活动产生的残留物数量有关，平均占收集材料的 20%左右。
