Sustainability Evaluation Of Wastewater Treatment Technology Based On LCA And Multi Criteria Decision Method

The sustainability evaluation of wastewater treatment technology is one of the important means to promote the sustainable development of wastewater treatment.The study attempts to build a set of sustainability evaluation index system and method of sewage treatment technology,in order to provide decision support for the selection of sustainable technology in the field of sewage treatment.Using the methods of literature research and field research,a sustainability evaluation index system covering four first level indicators of environmental,technological,economic and social factors,nine second level indicators of non-living ecosystem impact,human health impact and ecotoxicity impact,and 31 third level indicators of global warming,ozone layer destruction and acidification is constructed,and AHP is used to weight the index system.According to the different characteristics of specific indicators,the corresponding calculation method is used to determine the index value of three-level environmental,technical,economic and social indicators.According to the different evaluationneeds,the comprehensive evaluation index method and the first level index optimization rate evaluation method are used to comprehensively evaluate the sustainability of sewage treatment technology.Taking MBR membrane treatment technology as the evaluation technology and A~2/O technology as the benchmark technology,the sustainability evaluation index system and method of wastewater treatment technology were empirically studied.First hand survey data were obtained through field interview and questionnaire on sustainability evaluation of sewage treatment technology.Comprehensive evaluation index method and first-class index optimization rate evaluation method were used to calculate the indicators.The comprehensive evaluation index I=1.3557 obtained by comprehensive evaluation index method.The comprehensive evaluation index results show that MBR membrane treatment technology is better than A~2/O benchmark technology in overall sustainability.By using the first level index optimization rate evaluation method,four first level index optimization rates of environment,technology,economy and society were obtained,which were:-0.91%,12.14%,-0.39%and8.46%,respectively,which show that MBR membrane treatment technology is superior to A~2/O benchmark technology in technical and social factors,and slightly lower than A~2/O benchmark technology in environmental and economic factors,which is consistent with the heavy pollution and high power consumption of membrane treatment technology.The conclusions of the two evaluation methods are consistent with the enterprise decision-making results and the actual problems of membrane treatment technology,which verifies the feasibility of the evaluation index system and evaluation method.In the study,literature research and field research methods were used to build a set of sustainable evaluation index system and evaluation method of sewage treatment technology in line with China’s national conditions,and the operability and rationality of the index system and evaluation method were verified through empirical research.It is expected that the sustainability evaluation index system and evaluation method can provide decision support for the selection of sustainable technologies in the field of wastewater treatment.