Life Cycle Assessment Of The Control Technique Of Lake Eutrophication

Lake sustains the development of human beings, however, in recent years, withthe rapid development of human society and economy, the development activitiesdamaged the environment and impacted the ecological balance of the lake. Part oflakes in our country appeared the phenomenon of eutrophication. Life cycleassessment is a new type of environmental management tool, it can evaluate theenvironmental effect of product, process or production activities through the analysisof input and output of the system. The LCA of the lake eutrophication controltechnology have great significance on the selection of technology and discovery of thepotential improvement opportunity.Based on the two main goals of the life cycle assessment, the LCA results of thelake eutrophication control technology were analyzed in this research, the potentialimprovement opportunities were found and could be used as decision basis. SimaPro7.3.3software and CML2baseline2000evaluation method were used in this paper.In the LCA of point source control technology, the functional unit is10000m3/d,the object is the pretreatment, biological treatment, disinfection, sludge treatment anddischarge process of the A2/O process, oxidation ditch process and membranebioreactor process. Results show that the environmental impact of the three kinds oftechnology is mainly from the biological treatment phase, due to the chemicals, powerconsumption and transportation. Eutrophication and human toxicity are mainly fromthe discharge phase, due to the nitrogen and phosphorus discharged into water and theheavy metals discharged into the soil. According to the evaluation results, the studysuggested the improvement in energy structure and consumption, the use of chemicalsand sludge disposal aspects.In the LCA of non-point source control technology, the functional unit is1m3/d,the research is mainly about energy use, land use, raw materials consumption andemissions of land treatment, oxidation pond and surface flow constructed wetland.Results show that the constructed wetland system contribute most in the nineenvironmental impact categories except global warming. Land treatment systemcontribute least in all environmental impact categories, especially in eutrophication.With the LCA results of three techniques in5years,10years,20years and the applicability of the technology, the study provides certain decision basis for decisionmakers.