Environmental Impact Assessment Of Domestic Waste Incineration Process Based On Full Life Cycle

The production of municipal solid waste?MSW?is increasing day by day,which has a great impact on the environment due to the generation and treatment of MSW.At present,incineration of refuse is one of the most effective means of waste reduction.However,due to improper site selection,unscientific treatment technology,confused operation and management,incomplete reduction of pollutants and leakage of pollutants under accident conditions,there are certain environmental risks in the operation of municipal solid waste incinerator,which poses a major threat to the surrounding environment.In this paper,the environmental impact assessment system and the corresponding fuzzy comprehensive evaluation model for municipal solid waste incineration process are constructed,and the environmental impact assessment of a municipal solid waste incineration plant in Shandong Province is carried out by using the model.This paper mainly studies the following aspects:?1?Based on the idea of life cycle,the evaluation indexes are screened from the whole process of municipal solid waste?MSW?from temporary storage to incineration,then to landfill,and the comprehensive management of each process.The environmental impact assessment system and evaluation model of MSW incineration process are established.The evaluation index is explained and analyzed,and the reasonable evaluation criteria are determined.?2?Based on the evaluation index system of environmental risk impact in municipal solid waste incineration process,the index system will be constructed by the analysis method of target tree.Through field investigation and questionnaire survey,the relative importance of each index in the evaluation system is obtained.Then the judgment matrix is constructed by analytic hierarchy process,and the weights of each index are calculated by MATLAB software and Excel software.Thus,the temporary storage factor set includes odor treatment system and leachate treatment system;incineration factor set includes incinerator system and flue gas treatment system;landfill factor set includes fly ash treatment system;comprehensive management factor set includes management level,policies and regulations;and the concentration of NH₃,H₂S and A at the plant boundary contained in the above seven factors.Thiol concentration,effluent COD_Crr concentration,effluent ammonia nitrogen concentration and other 18 evaluation indicators.?3?By using the four-level fuzzy mathematics comprehensive evaluation model and three times of fuzzy transformation from the index level to the target level,the target tree index system is evaluated from the bottom level to the top level,and the comprehensive evaluation results of the index level,the factor level,the criterion level and the target level are obtained.?4?Taking a waste incineration plant in Shandong Province as an example,its environmental impact grade was evaluated and analyzed.According to the fuzzy comprehensive evaluation model,the membership matrix of 18 indicators was determined,and the comprehensive evaluation results of environmental risk during the operation of the municipal solid waste incineration plant were calculated:grade I 0.1031;grade II 0.2410;grade III 0.0721;grade IV 0.0562;and grade V 0.According to the principle of maximum membership degree,the environmental impact level of municipal solid waste incineration treatment process belongs to"level II",which shows that the impact level of the municipal solid waste incineration plant on the surrounding environment is lower.?5?Combined with the results of fuzzy comprehensive evaluation,the indexes?COD of effluent and ammonia nitrogen of effluent?which have great influence on environment are predicted and evaluated by single factor evaluation method,technical guideline of environmental impact assessment and groundwater simulation method,and the leakage risk of COD and ammonia nitrogen in Leachate under abnormal and accident conditions is judged.At the same time,according to the on-line monitoring data,the single factor evaluation method is used to assess the status of groundwater environment and to judge and evaluate the quality of groundwater in the region.According to the results of current situation evaluation,the total hardness,total soluble solids,sulfate,permanganate index,chloride,ammonia nitrogen,iron and manganese in each monitoring point exceed the standard in varying degrees.The reasons for exceeding the standard are affected to a certain extent by the garbage incinerator,and the main reason is that the current situation exceeds the standard.According to the prediction results,it can be seen that under abnormal or accident conditions.The influence of COD and ammonia nitrogen in leachate on groundwater environment is very small,but concrete anti-seepage measures and early warning schemes need to be formulated.