| Industrial wastewater which is a main reason of environmental pollution.Industrial wastewater treatment is also accompanied by certain environmental impacts.Life Cycle Assessment(LCA)provides a practical approach to environmental load analysis that effectively analyzes,evaluates,and predicts environmental loads generated during industrial wastewater treatment.In the existing LCA-based industrial wastewater treatment environmental load research,most of the research objects are laboratory-stage process devices.Most of the LCA methods used are“local generalization”methods,which can be used all over the world and all walks of life.LCA methods for various industries.However,only relying on the actual industrial wastewater treatment plant,and can fully consider the strong local characteristics of industrial wastewater treatment(protecting local water bodies),relevant LCA analysis can lead to more realistic and instructive evaluation results and optimization strategy.Therefore,this paper adopts the LCA method(Site-specific LCA)developed based on local characteristics,and takes the wastewater treatment station of a paper mill in Heilongjiang as the research object,and studies the life cycle environmental impact of industrial wastewater treatment in paper mill sewage treatment station.In this study,eight environmental catalogues of acidification,eutrophi cation,ecotoxicity,human toxicity,non-biological resource consumption,ozone depletion,fossil resource consumption and climate change were selected,and the environmental load generated by the sewage treatment station was operated for one year.Characterized calculations(using the CML method).The results of the study show that the environmental impact due to power consumption is the maximum in all eight environmental catalogs.Among them,in the acidification environment catalogue,electricity consumption accounts for 83.73%;in the eutrophication catalogue,electricity consumption accounts for 94.77%;in the water body ecotoxicity catalogue,electricity consumption accounts for 93.37%;in the human toxicity catalogue,electricity consumption accounts for 87.43%;in the non-biological resource consumption catalogue,electricity consumption accounts for81.97%;in the fossil resource consumption catalogue,electricity consumption accounts for 76.25%;in the climate change catalogue,electricity consumpt ion accounts for 84.80%;in the ozone depletion environment catalogue,power consumption Accounted for 43.64%.Based on the standardized factors and weighting methods developed specifically for the Chinese background in the Site-specific LCA method,this study conducted a localized table for the characterization results obtained above.The results show that the results obtained by the Site-specific LCA method can more fully reflect the impact of industrial wastewater treatment on the local environment.The main reason is that the contribution of water pollutants(mainly COD)accounts for 54.85%-95.42%of the results obtained by the Site specific LCA method,which is higher than the proportion of the results obtained by the international general LCA method(10.62%-25.54%).This study further adopted the localized eco-efficiency analysis method developed based on the Site-specific LCA method,and analyzed that the sewage treatment station has high ecological efficiency when running under the current standard(50%higher than other scenarios).It indicates that the optimized design of the process based on the results obt ained by Site-specific LCA is feasible.By analyzing the optimized LCA results,the current sludge incineration treatment will cause serious environmental hazards.Therefore,the optimized sludge treatment scheme is 63.7%for sludge for agricultural composting and 37.3%for biogas fermentation,and biogas produced(0.11 m~3).Biogas/m~3 treated water can be converted to 0.68 kWh/m~3 of electrical energy,which is sufficient to meet the full electricity demand of the sewage treatment station. |
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