Study On The Degradation Of 2,4,6-TCP Using Modified Carrier Supported Nano-zero-Fe/Ni

Chlorophenols（CPs）compounds are highly toxic and difficult to handle pollutants,which are extremely harmful to human safety and the environment.2,4,6-Trichlorophenol（2,4,6-TCP）is a highly toxic substance among chlorophenols and it is difficult to remove.In this paper,2,4,6-TCP is used as the research object,and the modified gel and microspheres are used as carriers to support zero-valent nano-iron/nickel bimetal,and its removal is studied.The specific research content is as follows:Using PNIPAM gel as the first polymer,4 modified PNIPAM/PHEMA,PNIPAM/PAEMA,PNIPAM/PAA,PNIPAM/AMPS gel carriers were prepared by adding the second monomer or the second polymer;PS microspheres and PS-CH₂Cl were prepared by emulsion polymerization and modified to prepare PS-HSO₃,PS-CH₂-N⁺（C₂H₅）₃Cl^-,PS-CH₂-imidazole microsphere carriers.The zero-valent nano-iron/nickel bimetal was loaded on the carrier by the chemical reduction method,and a variety of supported nano-iron/nickel composite materials were successfully prepared.Characterization test of the synthesized carrier by SEM,FTIR and other methods:SEM test results show that the modified gel carrier has a pore structure with a pore size of 5-60μm;the modified microsphere carrier has a smooth surface and the particle size of the microspheres is around 300nm or 400nm;FTIR test results show that each gel carrier and microsphere carrier have characteristic peaks of each group,and the modified carrier is successfully prepared.SEM,SEM-Mapping,EDS and XRD are used to characterize and test the loaded composite material:the metal particles can be clearly seen on the SEM image.Except for（PS-SO₃H）-nZVFe/Ni material,the bimetallic particles have no agglomeration.Phenomenon;SEM-Mapping surface scanning analysis shows that Fe and Ni elements are evenly distributed on the surface of gel pores and microspheres;through EDS energy spectrum analysis,it can be seen that the main element composition of the loaded material is C,O,Fe,Ni,And different carriers have different loading conditions of Fe-Ni bimetal.The phase composition of the material was analyzed by XRD,and zero-valent iron and nickel peaks were detected at 2θ=43.59°and 50.67°respectively,indicating that the iron-nickel bimetal was successfully loaded on the carrier.Using the controlled variable method,using PNIPAM/PHEMA-nZVFe/Ni to remove 2,4,6-TCP,the best experimental conditions are as follows:the molar ratio of Ni/Fe is 12.5%,the initial p H range of the solution is 5-6.8,the dosage of gel carrier is 0.3 g,and the reaction temperature is 25℃.The reduction process of 2,4,6-TCP was analyzed:2,4-DCP,2-CP,4-CP are produced during the degradation and reduction process of 2,4,6-TCP,which is finally completely degraded into P.The degradation process of 2,4,6-TCP under the optimal conditions was analyzed kinetics,and the fitting results showed that the degradation process conformed to the first-order reaction kinetic model.PNIPAM/PHEMA carrier reusability performance and PNIPAM/PHEMA-nZVFe/Ni material storage performance is better.The effect of modified gel carrier on the removal of 2,4,6-TCP was studied.2^#PNIPAM/PAA-nZVIFe/Ni and 1^#PNIPAM/AMPS-nZVIFe/Ni can completely remove 2,4,6-TCP,the removal rate of PNIPAM/PAEMA-nZVIFe/Ni for 2,4,6-TCP is only 73.53%.Comparing with PNIPAM-nZVIFe/Ni material showed that-SO₃H and-COOH functional groups accelerated the dechlorination of 2,4,6-TCP,while-NH2hindered the progress of the dechlorination reaction.The kinetic analysis and fitting results showed that the degradation processes of the three modified materials for2,4,6-TCP were in line with the first-order reaction kinetic model.The reusability of2^#PNIPAM/PAA and 1^#PNIPAM/PAMPS gel carrier and the storage performance of the prepared composite materials were good.Research on the removal of 2,4,6-TCP by microspheres showed that PS-CH₂Cl-nZVFe/Ni,PS-CH₂-N⁺（C₂H₅）₃Cl^--nZVFe/Ni,PS-CH₂-imidazole-nZVFe/Ni can remove 98%-100%of 2,4,6-TCP.Through the analysis of the product during the reaction and the adsorption analysis of 2,4,6-TCP by the microspheres,it is found that the removal of 2,4,6-TCP by（PS-CH₂Cl）-nZVFe/Ni is a process of adsorption and reduction,the removal process of 2,4,6-TCP by（PS-CH₂-N⁺（C₂H₅）₃Cl^-）-nZVFe/Ni and（PS-CH₂-imidazole）-nZVFe/Ni is adsorption.The reusability of PS-CH₂Cl,PS-CH₂-N⁺（C₂H₅）₃Cl^-,PS-CH₂-imidazole microsphere carrier is good.