Degradation Of Chloronitrobenzene Using Chloromethylated Polystyrene Microspheres Supported Nanoscale Zero-valent Iron And Nickel

Chloronitrobenzene is a typical compound with "three-inducing" effect and genotoxicity.It is a necessary intermediate in production of pharmaceutical,pesticide and fue.Chloro-nitrobenzene has stable chemical properties and biodegradability,and easy in the water,soil and other long-term accumulation of the environment,and easily affect the biological health through bioaccumulation.As a result of the rapid growth of the production scale and large-scale applications of chlorinated nitrobenzene have led to the detection of different concentrations of pollution in many rivers,lakes and even groundwater in China,which seriously threaten human health and ecological environment.Therefore,it is of great practical significance to study the degradation of these substances.In recent years,it has been found that zero-valent nano-iron and iron-based bimetallic can effectively degrade nitrobenzene.However,because of the inherent magnetic properties of nano Fe/Ni particles,it has easy agglomeration,easy oxidation and poor stability,thus restricting its effect in practical application.Therefore,the choice of suitable carrier materials and loading methods,prepara stable performance,high reactivity of nano-Fe/Ni material,become the focus of attentionIn this paper,PS microcrystals?PS-CH₂-Cl?were prepared by free radical polymerization,and then highly chloromethylated PS microspheres and triethylamine were reacted to obtain quaternized PS Microspheres?PS-CH₂-N+?C₂H₅?3Cl-?.The adsorption capacity of these three microspheres to nitrobenzene and p-nitrochlorobenzene was investigated,it was found that the quaternized microspheres?PS-CH₂-N+?C₂H₅?3Cl-?had good adsorption ability to nitrobenzene and nitrochlorobenzene?adsorption rate was about 35%?,and the adsorption process substrate stability is better.?PS-NZVFe/Ni?was prepared by semi-quasi-aminated microspheres as the carrier,and Fe/Ni was prepared by liquid phase reduction.The microspheres?PS-NZVFe / Ni?were prepared by SEM scanning electron microscopy,EDSspectroscopy,X Ray diffraction?XRD?,BET specific surface area analysis and so on.The effects of PS-NZVFe/Ni on the catalytic reduction and dechlorination of PS-NZVFe/Ni were investigated.The effects of pH,pH and temperature on the degradation of PS-NZVFe/Ni were investigated,and the optimum reaction conditions were determined.The effects of PS-NZVFe/Ni on the degradation of the other four different chlorinated nitroaromatics were investigated.The degradation efficiency and reaction rate of four different substances?2,4-dichlorophenol,o-chloronitrobenzene,tetrachloronitrobenzene and pentachloronitrobenzene?were compared.The results showed that:?1?Quaternized polystyrene microspheres?PS-CH₂-N+?C₂H₅?3Cl-?as a supported Fe/Ni carrier can solve the problem of nano Fe / Ni easy agglomeration,and supported nano Fe/Ni material has a large specific surface area,better physical adsorption and reduction of dechlorination better synergistic effect,improve the removal efficiency of the target.?2?PS-NZVFe/Ni for degradation of p-chloronitrobenzene in the experiment showed that: 1.0g PS-NZVFe/Ni?Ni/Fe ratio of 2.0%?at 25 ?,the treatment pH of 3-7,250 mL p-CNB conversion was above 99.0%.After 90 min,the p-CNB was completely reduced to the biodegradable low-toxic aniline at 90 min.Its degradation speed,high degradation efficiency,reflecting the PS-NZVFe / Ni excellent degradation ability.?3?PS-NZVFe / Ni expansion degradation of other chlorinated aromatic substances.Under the optimum conditions,2,4-dichlorophenol,1-Chloro-2-nitrobenzene,tecnazene and pentachloronitrobenzene were completely degraded.The degradation reaction was in accordance with the pseudo-first order reaction kinetics model.The reaction rate Size comparison: pentachloronitrobenzene>tecnazene> 2,4-dichlorophenol>1-Chloro-2-nitrobenzene.The reaction rate is related to the amount of carrier adsorption and is related to the type of substituents on the benzene ring.Chlorinated aromatic hydrocarbons are more easily degraded as the degree of chlorination increases.