Reductive Dechlorination Of Chlorophenols And Their QSPR Studies

Chlorophenols(CPs),a kind of environmental priority pollutants,are highly recalcitrant towards to both chemical and biological degradation and carcinogenicity,mutagenicity and teratogenicity in our environment.A series of related researches have been studied how to degradation chlorophenols in the water domestic and overseas.Up to now,they have been under active research in the field of environment remediation and large numbers of measures have been developed.Due to iron-containing nanoparticals'large surface areas,high surface reactivity and application flexibility,they provide effective solutions to some of the most challenging environmental cleanup problems.In this dissertation,firstly,iron-containing nanoparticals were synthesized by chemical reduction and replacement deposition method.The size,morphology and chemical components of nano particles were investigated by instrumental methods such as TEM(transmission electronmicroscopy),XRD(X-ray diffraction)and EDS(energy dispersive X-ray detector)analyses.Secondly,The reductive dechlorination rles of ten chlorophenols(CPs)(2,4,6-TCP?2,3,5-TCP?2,3,6-TCP?2,4,5-TCP?2,3,4-TCP?3,4,5-TCP?2,3,4,5-TeCP?2,3,4,6-TeCP?2,3,5,6-TeCP and PCP)by Pd/Fe bimetallic nanoparticles under Pd weight ratio 0.1371%were investigated.The degradation samples were sacrificed to measure the components and concentrations of the CPs and their degradation products by high performance liquid chromatography(HPLC)at preselected time intervals.Moreover,The molecular electronegativity-distance vector(MEDV)were employed to describe the chemical structure of 36 chlorinated organics.Quantitative Structure-Property Relationship(QSPR)model that correlated the reductive dechlorination performance and molecular structures of chlorinated organic compounds was developed.The quality of the model was validated by internal cross-validation procedures and external data validations.The research results indicated that the average size of the iron-containing nanomaterials was 25-50nm.Pd dispersed on the surface of the iron discontinuously.The degradation rules of all the dechlorination reactions by nano Pd-Fe can be described well by the pseudo-first-order kinetic model.The order of the reaction rate constants often CPs was 2,4,5-TCP>PCP>2,3,5-TCP>2,3,5,6-TeCP>2,3,4,5-TeCP>2,3,6-TCP>2,3,4,6-TeCP>2,4,6-TCP>2,3,4-TCP>3,4,5-TCP,which was relevant to their molecular structure.Furthmore,MEDV descriptors were proposed to express the molecular stuctures.of 36 chlorinated organics,and the predictive QSPR model correlated the reductive dechlorination performance and molecular structures of chlorinated organic compounds was constructed.The high values of r2 and q2LOO present good estimation ability and stability of the model.The prediction power for external samples was validated by the model developed from the training set,which can be a guide for further study in this research field.