Research On Life-cycle Cost Of Sewage Treatment Plant Under Risk

In recent20years, the Chinese government has paid so much attention on theeconomic development that ignored the harmonious development among economy,society and environment, which leaded to the deterioration of the eco-environment. Asthe water environment is related to the people closely, it attracts more attention. Withthe rapid urbanization and industrialization, the discharge of sewage has increased yearby year. Meanwhile there are many problems such as the high operation cost, quantityshortage, the low anti-risk ability in sewage treatment facilities. Take the two intoconsideration, part of the sewage is discharged without treatment. The dissertationfocuses on estimation of the life-cycle cost of sewage treatment plant in the decisionstage, to supply the cost index for scheme comparison. In this way, it can decrease theoperation cost and enhance the anti-risk ability.In this dissertation, the life-cycle cost of sewage treatment plant is taken asresearch object. Firstly the life-cycle cost is decomposed by the stages, and thedissertation recognizes the life-cycle cost and the influence factors. Secondly with thescheme comparison as the objective, the dissertation deletes the common cost, and onlyestimates the differential cost, such as the cost of land usage, construction, operationand demolition. Furthermore, it erects the estimation model of life-cycle cost. Thirdly,there are many factors such as the long life-cycle, risks that can have much influence onthe life-cycle cost. So the dissertation recognizes the risks of the life-cycle fully, anderects the risk index system. To simply the analysis and get the key risks, thedissertation takes the analysis hierarchy process (AHP) to sort the risks. Thus we getthe key risks. Then the dissertation estimates the probability of the key risks byconsulting the experts. Fourthly the dissertation has sensitivity analysis of the life-cyclecost in the combination of some key risks, and gets the life-cycle cost. Then based onthe probability and the life-cycle cost in the risk combination, the dissertation gets theexpectation of the life-cycle cost. Fifthly, based on the above analysis, the dissertationestimates the cost units combined with the case. Then it erects the estimation model ofthe life-cycle cost of the sewage treatment plant. Furthermore it chooses the key risks,and gets the probability and the life-cycle cost in some risk combination. Finally thedissertation gets the expectation of the life-cycle of the sewage treatment plant.The research on this topic can help to avoid the problems of the disregard of theoperation cost, the life-cycle risks and so on, so that to increase the loading rate of thesewage treatment plant. It can provide a new thought for the similar projects in thedecision stage. Meanwhile it promotes the application of the method of life-cycle costanalysis in the construction of environmental infrastructure in some degrees.