Evaluation Research Of Municipal Solid Waste Systems In Shuozhou City Based On Life Cycle Assessment Model For Environmental Impacts

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.