【作者】 张旭；

【导师】 陆文静； 袁进；

【作者基本信息】 清华大学 ， 环境工程（专业学位）， 2012， 硕士

【摘要】 针对中国北方小型城市生活垃圾的特点和处理处置现状，本文以山西省朔州市的生活垃圾处理系统为基础，利用生命周期评价方法开展其全过程的环境影响评估研究，为中国北方同等规模和经济水平的中小型城市建立可持续的生活垃圾管理方案提供理论依据和真实案例。本研究中，首先通过实验室分析、现场监测获取垃圾组分、元素、热值及填埋场渗滤液成分等参数，通过调研垃圾处理系统的规划、作业报告、设施运行统计数据等获取了垃圾运输及转运作业参数、填埋场及焚烧厂的作业参数和工艺参数，并通过对比调研同类技术和参照模型默认数据库获取部分上下游外部单元的生命周期数据。之后，基于朔州市生活垃圾处理系统的现状，针对以垃圾卫生填埋技术为主的填埋处置方案和以流化床焚烧炉焚烧发电为主的综合处理方案，建立了共十个处理系统的不同模拟情景，并利用固体废物系统生命周期评价模型软件EASEWASTE，开展不同情景对温室效应、酸雨、富营养化、生态毒性等环境影响的定量化模拟评估。研究结果表明，在朔州市当前生活垃圾填埋系统下，与渗滤液直排相比，渗滤液采用回灌方式进行处理，能够避免大部分对生态毒性和人体毒性的环境影响，然而由于能源消耗略有增加、垃圾降解和产气略有增强，对大气环境有轻微的影响。填埋气未得到控制时，甲烷是造成温室效应和光化学烟雾的主要污染物，采用填埋气直接燃烧技术，能够避免系统98%的温室效应以及约90%的光化学烟雾、酸雨和富营养化的影响。对于以焚烧为主的综合处理系统，采用过量辅助煤焚烧时所释放的CO2，是该系统造成温室效应的主要因素，而焚烧发电能够一定程度抵消燃煤发电对酸雨、光化学烟雾和富营养化等环境要素的影响；采用适量辅助煤的垃圾焚烧，对系统造成的温室效应有明显改善。由于原生垃圾的低热值和高灰渣含量，朔州市生活垃圾的无辅助煤直接焚烧并不可行，通过源头分离2/3的灰渣后焚烧剩余垃圾，对温室效应、酸雨、富营养化以及土壤生态毒性等均有不同程度的改善作用，是朔州市一种可行的生活垃圾处理体系。经济性分析表明，由于电能回收，焚烧技术的总体经济性略高于填埋处置，综合分析认为以垃圾焚烧发电为主的综合处理方案为朔州市相对更优的垃圾管理方案。研究结果对我国北方中小型城市类似生活垃圾管理系统的评估与优化具有重要的理论和现实意义。更多还原

【Abstract】 Based on the municipal solid waste system in Shuozhou, Shanxi province,environmental impact evaluation of the possible systems was performed by using lifecycle assessment (LCA) method. In this study, the composition and element of wasteand landfill leachate were obtained by laboratory analysis and in-situ monitoring. Thedata on waste collection, transportation, and landfill and incinerator operations werecollected from the system planning reports, operational reports and operationalstatistical data. Some external data referred to those of similar technologies and defaultdatabase in the software applied. According to the landfill strategy and the integratedstrategy involved incineration, ten scenarios were established for modeling by anLCA-based-software EASEWASTE and evaluating their potential environmentalimpacts to global warming, acidification, nutrient enrichment, ecotoxicity and so on.The results showed that, in the landfill strategy, leachate recirculation can avoidmost impacts to ecotoxicity and human toxicity comparing with leachate discharge.However, the impacts to atmosphere increased to a small extent due to more energyconsumption and more gas emission. In landfills without gas treatment, methane is themajor contributor to global warming and photochemical ozone formation. Flaring oflandfill gas can efficiently remove98%greenhouse gases and avoid approximately90%impacts to photochemical ozone formation, acidification, and nutrient enrichment. Inthe integrated strategy with incineration, CO2released from incinerator with excessauxiliary coal was the main factor of the system for global warming. Energy recoveryfrom incineration can counteract the impacts to acidification, photochemical ozoneformation, and nutrient enrichment derived from coal power generation. Incinerationwith adequate auxiliary coal can efficiently improve the behavior to global warming.Because of the low heating value and high content of dust, incineration withoutauxiliary fuel is considered infeasible for the waste system in Shuozhou. However, thestrategy involving source separation of dust and incineration of the rest waste presentedsignificant benefit to global warming, acidification, nutrient enrichment, and ecotoxicityvia soil, and thus was considered a promising solution to the waste management system.According to the financial analysis, waste incineration showed less economical thanlandfill. Therefore, given both the environmental and the economic aspects, theintegrated strategy with dust separation and waste incineration can be determined as theoptimal strategy of the waste system in Shuozhou. The results can provide importantevidence for the evaluation and optimization of similar municipal solid waste system insmall cities in northern China.更多还原