Vanadium(Ⅴ)is an emerging contaminant reported in wastewater along with the increasing of alloy manufacturing,chemicals,new energy fields as a significant national strategy resource.In this study,a quaternary ammonium modified silica(SiO2@DMOA)material was synthesized for the adsorption of vanadium(Ⅴ)in aqueous so-lution.The results of TGA,FT-IR,SEM,and EDS confirmed the successful synthesis of SiO2@DMOA composite.Under the conditions of solution volume of 20 mL,vanadium(Ⅴ)concentration of 2 mmol/L,solution pH of 3.3,con-tact time of 15 minutes,and temperature of 298 K,the adsorption capacity for vanadium(Ⅴ)by SiO2@DMOA was 38.97 mg/g.The pseudo-second-order reaction kinetics and Langmuir adsorption isotherm model indicated that the process of adsorbing vanadium(Ⅴ)by SiO2@DMOA was a surface monolayer chemical adsorption process,and the intra-particle diffusion model and Boyd model demonstrated that liquid film diffusion was the main limiting rate of this adsorption pro-cess.Thermodynamic studies demonstrated the feasibility and spontaneity of vanadium(Ⅴ)adsorption by SiO2@DMOA,with ΔH0>0,ΔS0>0 and ΔG0<0.The influence of ionic strength(NaCl)on adsorption was found to be negligible at con-centrations of less than 0.1 mol/L.Furthermore,within pH range of 3-5,the maximum separation factor(βV/Cr)between vanadium(Ⅴ)and chromium(Ⅵ)was 135.42.The adsorption efficiency of SiO2@DMOA did not show any significant at-tenuation after five cycles of adsorption-desorption experiments.
维普
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