Research On Credibility Theory Based Fuzzy Analytic Hierarchy Process With Application To The Selection Of Treatment Technology For Hazardous Chemical Pollutions

With the rapid development of its chemical industry,China has become the second-largest chemicals production and application country in the world.These hazardous chemicals usually have complex properties.Severe environmental pollution accidents caused by the leakage or explosion of chemicals and their compounds during production,transportation,storage and waste disposal have occurred.Compared to general environmental pollution incidents,the pollution caused by heavy metals is high intensity,spreads rapidly and has consequences that are more difficult to eliminate.Besides,in different natural environments and social circumstances,the best treatment technologies for the same chemical accident could be different.Therefore,it is important to solve a multi-criteria decision problem which is to determine the most appropriate treatment approach with high accuracy when a pollution incident happens.Analytic hierarchy process is the most famous method in multi-criteria decision making.It has become an important tool for system analysis,applied in the following three steps:(1)constructing a decision hierarchy;(2)measuring and determining the local weights of the components of the hierarchy;(3)synthesis to reach an overall score.However,analytic hierarchy process ignores the fuzziness in decision-making environment,and fuzzy analytic hierarchy process lacks the calculation method based on rigorous theoretical basis.In this study,we extend analytic hierarchy process in fuzzy environment based on credibility theory,and propose a credibilistic analytic hierarchy process,which makes the decision process more accurate and efficient.Then we apply the credibilistic analytic hierarchy process to select the most suitable treatment technology for mercury pollution in water.The research contents of this paper are as follow.(1)Firstly,the importance of the emergency treatment of pollution accidents caused by hazardous chemicals is introduced.The theoretical research and application of analytic hierarchy process and fuzzy analytic hierarchy process are summarized,and the advantages and disadvantages of current research are analyzed.(2)Secondly,we introduce analytic hierarchy process,fuzzy analytic hierarchy process,some basic concepts and definitions in credibility theory,and the principle of justifiable granularity.These theories provide a theoretical framework and basis to the credibilistic analytic hierarchy process,which is an improved analytic hierarchy process approach in fuzzy environment.(3)Thirdly,within the framework of credibility theory,we propose a credibilistic analytic hierarchy process approach by taking advantage of the principle of justifiable granularity.The expected value criterion,optimistic value criterion and pessimistic value criterion are presented and the corresponding fuzzy simulations are used to approximate alternatives' weights.(4)Finally,we establish a framework based on credibilistic analytic hierarchy process on selecting the most appropriate treatment technology for hazardous chemical pollutions in uncertain natural environments and social circumstances.An application of credibilistic analytic hierarchy process on selecting treatment technologies for mercury pollution in water is presented to demonstrate the efficiency of the proposed approach.