The Analysis Of Technology Selection And Optimizing Application Of Soil Remediation In Xiang River Basin

With the rapid development of industrialization and urbanization, more and more wastes are released into the environment, causing serious environmental pollution issues and adverse effects. Therefore, it is urgent to conduct the environmental remediation, in which, the soil remediation, as a representative example, is very complex and difficult due to characteristics of soil contamination, such as multi-sources, compound pollutions, large quantities, wide area, strong toxicity. Recent years, a wide attention and large investment from various fields of the society have been paid to the soil contamination and remediation with a certain progress being made. While with the increasing demand of soil remediation, the significance of research on technology selection and management for site remediation projects is highlighted. Therefore, this paper applies Multi-Criteria Decision Analysis (MCDA) into remediation technology selection which can integrated many site remediation factors to ensure the scientific decision and promote the development of site remediation. For example, the study on the remediation technology selection and optimization of application for Xiang River Basin, which is a state-led remediation test area due to its serious heavy metal pollution, can provide guidance of the environmental remediation for this area and even throughout the country.Firstly, this paper studies the key management area of heavy metals pollution of Xiang river Basin in three aspects:retrospectively analyze the development of soil remediation technology and project decision-making; state the current situation of its serious heavy metal pollution in this area from the characteristics of natural resources and socio-economic development; analyze the main reason and draw a conclusion that it is the industrial structure of Xiang river Basin being dominated by heavy-chemical industry that lead to the serious heavy metal pollution on the farmland and bottom sludge in the mine lot.Secondly, this paper tries to set up an evaluation model AHP-TOPSIS by combining two common methods (Analytic Hierarchy Process (AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS)) of MCDA to select the proper soil remediation technologies for the key management area of Xiang river Basin. The first step is to conduct a primary technology selection by considering the influence factors on the site remediation project and the pollution situation in the study area to build up the structural evaluation system. Then evaluate the index and primary selection through questionnaires from experts, confirm the index weight by using AHP to process the data, carry out the final ranking of the primary technology by using TOPSIS, and finally obtain the evaluation result on the suitability ranking of major technologies in the key management areas of the Xiang River Basin: Solidification/Stabilization> Phytoremediation> Soil Washing/Flushing>Chemical Oxidation>Electrokinetic Treatment.At last, the author puts forward some reasonable suggestions, such as technology innovation, development of environmental-friendly model, optimized cost structure and comprehensive remediation technology, to promote the optimizing application and the applicability of the S/S technology on the soil remediation in Xiang River Basin.