Decision-making Model For Remediation Schemes And Hybrid Chemical Oxidation-thermal Desorption Process For Organic Contaminated Soils

Soil contamination has become a key factor which restricts the sustainable development of society.The comprehensive preventions and remediation actions of contaminated soil are imperative.The aim of this dissertation is to deal with several practical problems existed in the soil remediation industry.In this background,an evaluation and determination model for soil remediation schemes and a hybrid oxidation-thermal desorption process are proposed.For a practical contaminated site,the selection of the optimum remediation scheme is difficult due to its high complexity in contaminants,geological conditions,usage and even urgency diversity in remediation technologies,etc.Herein,a sustainable decision support hierarchical model has been developed to select,evaluate and determine preferred soil remediation schemes comprehensively based on modified analytic hierarchy process(MAHP)from economic,environmental and technological aspects.This MAHP method in the model combines competence model and Grubbs criteria with conventional AHP.It not only considers the competence differences among experts in group decision,but also adjusts the big deviation caused by different experts' preference through sample analysis.This conversion allows the final remediation decision more reasonable.Beyond soil remediation,this MAHP method could also be applied in other fields referring to multi-criteria group decision making.For the soil contaminated by 2,4-dimethylaniline,limited research has been conducted on the treatment method.Herein,a hybrid oxidation-thermal desorption process has been proposed to deal with it.Relevant experiment is carried out to test the feasibility of the method.The result shows that the application of the method in the treatment of soil contaminated by 2,4-dimethylaniline not only lowers heating temperature and shortens treatment time,but also could avoid the secondary contamination compared with chemical oxidation solely.Based on experimental data,the influence of ozone concentration in the carry gas,heating temperature and moisture content in soil on the remediation efficiency are explored.Meanwhile,the kinetic behavior of the remediation process is investigated and fitted with a mathematic model.