The Calculation Of The Transfer And Transformation Properties For The Typical Organic Pollutants

Environmental pollutants have a large amount and various kinds.These pollutants can also be transferred through air,water,soil,sediment and other environmental media,posing a serious threat to the environment and human health.Environmental pollutant migration is strongly influenced by its basic physical properties,such as the heat capacity of ideal gas,vapor pressure,evaporation enthalpy,etc.,which have important influence on the migration of pollutants.At the same time,these pollutants may also interact with free radicals,such as hydroxyl radicals,nitrogen radicals,ozone,and so on,which will directly affect the removal of pollutants or the generation of secondary pollutants.Quantitative structure-property relationship(QSPR)is a method that uses molecular structure variables to predict properties,and it has played an important role in drug design,environmental ecological assessment and other fields.Therefore,using QSPR method,the ideal gas heat capacity at constant pressure of organic pollutants,enthalpy of evaporation,reaction rate constants between pollutants and NO3 radicals were studied.The research results has important guiding significance to the migration process of pollutants,the evaluation of ecological environment,and the safe use of the organic matters.In this study,several new descriptors were proposed based on the previous research results of our research group,and the model was established by using multiple linear regression method.In this study,cross validation,Y-randomization validation,external validation,mean absolute error,and application domain were used to verify the robustness and predictability of the model.This study has carried out the following three aspects of research,the research results are:[1]Calculation of the ideal gas pressure heat capacity of organic pollutants.In this research,a series of norm descriptors are proposed for the ideal gas constant pressure heat capacity.Then,a quantitative structure-property relationship modeling study on the ideal gas constant pressure heat capacity of 114 organic pollutants is conducted to calculate the relevant heat capacity values.The results show that the model established in this work can be effectively used in the calculation of ideal gas heat capacity,and the calculated values and experimental values are in good agreement.The relationship correlation coefficient square value R2 of the established model is 0.997,the training set and testing set square correlation coefficient values R2 were 0.998 and 0.997,the relationship coefficient square value Q2 of leave-one-out cross validation is 0.997.[2]Calculation of evaporation enthalpy of organic pollutants.This research used the above methods to establish a model for calculating the enthalpy of 471 typical environmental organic pollutants.The results show that the model can be effectively used to calculate the enthalpy of organic pollutants.The relationship coefficient squared value R2 of the overall regression of the model is 0.934,the squared relationship coefficient R2 of the training set and test set is 0.929 and 0.947 respectively,and the relationship coefficient square value Q2 obtained by the cross validation is 0.929.[3]Calculation of reaction rate constants of NO3 radicals towards organic pollutants.This research used the method mentioned above to modelling the reaction rate constant between organic pollutants and NO3 radicals,then,reaction rate constants between 180 typical environmental organic pollutants and NO3 radicals were calculated.The results show that the model can be effectively used to calculate the reaction rate constants between 180 typical environmental organic pollutants and NO3 radicals.The squared relationship coefficient R2 of the model was 0.839,and the squared relationship coefficient R2 of the training set and test set was 0.844 and 0.779 respectively,and the relationship coefficient squared value Q2 obtained by the cross-validation method was 0.662 Q2 greater than 0.5 is valid).In this study,three physical parameters of organic pollutants are modelled,using the QSPR method.The results show that this work,based on the molecular structure descriptors,could reflect the nature of organic molecular structures,at the same time,the established models could preferably describe the macroscopic properties of organic pollutants.As a consequence,this method has generality and universality.