Case Analysis And Life Cycle Assessment Of Separate Collection And Disposal Of Domestic Waste

With the rapid development of urban construction and social economy,the amount of domestic waste is increasing constantly,and the disposal of that has become an important task which can influence urban development.At present,most of the domestic waste is collected using a mixed-collection method which can result in complicated components of the collected domestic waste.Generally,landfill and incineration are used for disposal,which can not only occupy a lot of land resources but also cause low material and energy recovery efficiency and serious pollutant discharge that endanger human health and ecosystems.Combining the life cycle assessment method with the model of the household waste management system can not only provide the system with a high-level assessment,but also identify the key processes,key substances that affect the assessment,and provide the basis and optimization recommendations for industry and government decision-making departments.This paper investigates the domestic and foreign waste sorting collection and disposal models,and finds that because of the characteristics of biodegradable waste with high moisture content,low heat,rich organic matter,and biodegradable,biological treatment technology has advantages like low investment costs,small environmental pollution,and occupation of land,small area and so on.So this paper uses the life cycle assessment method and ReCiPe's midpoint and endpoint level indicators to evaluate the disposal of biodegradable waste,like landfill,biological aerobic compost,and anaerobic fermentation in the solar room.The study found that the normalized values for the environmental impact are-11.7,-2.18,and 0.30,respectively.Biological aerobic compost disposal scenario can obtain product organic fertilizer,the landfill disposal scenario collects landfill gas to generate electricity.These useful products can offset the environmental load required to produce these products,but solar anaerobic fermentation treatment scenario only emits various pollutants into the environment.Therefore,the biological aerobic compost disposal scenario has the lowest load on the environment among the three scenarios,followed by the landfill disposal scenario.We did sensitivity analysis of the anaerobic fermentation scenario of solar anaerobic fermentation treatment scenario and found that the life cycle impact potential of the scenario for energy and material recovery of the products is-25.04,which is significantly lower than the original scenario and biological aerobic compost scenario.In order to conduct a comprehensive environmental impact assessment of the household waste management system,this article takes the household waste management system in Hangzhou as an object and models it,and discusses the environmental load of mixed collection,classified collection,and different combinations of household waste treatment methods.This article focuses on the life cycle assessment of the classification and disposal of kitchen waste and other waste types in Hangzhou's household waste.The results show that among the 7 scenarios,the sorting collection is used to bio-aerobic compost for the collected kitchen waste,and environmental load for incineration of other waste is the lowest.We identify the environmental impact categories,key processes and key substances that have significant potential impacts on the life cycle environmental impact of domestic waste disposal scenarios.We found that climate change,freshwater eutrophication,fossil consumption,human toxicity,and particulate matter formation have a significant impact which provides data support for optimizing the domestic waste management system.