Study On Adsorption Of Copper,Lead And Phosphorus By Polyvinylidene Fluoride Blend Film And Modified Macroporous Chelating Resin

D751 macroporous styrene chelating resin has the advantages of stable chemical properties,high degree of functionalization,large degree of crosslinking,and good selectivity;polyvinylidene fluoride?PVDF?film has the characteristics of good thermal stability,strong oxidation resistance and high mechanical properties;and both have received much attention in the removal of pollutants from water.Therefore,D751 was modified by FeCl₃and LaCl₃for phosphate adsorption from solution,respectively;blended films were prepared by PEI and PVDF and used for the removal of Cu???and Pb???from solution.The adsorption behavior and adsorption mechanism of the four systems were performed in batch mode.The relevant materials were characterized by Fourier transform infrared?FTIR?,scanning electron microscopy?SEM?,photoelectron spectroscopy?XPS?,isoelectric point measurement?p Hzpc?,specific surface area analysis?BET?and raman analysis?Raman?.D751-Fe and D751-La were obtained using FeCl₃and LaCl₃as modified ageent,respectively;and the adsorption performance of two materials on phosphate was explored.The results revealed that the adsorption capacity toward phosphate was obviously improved.The adsorption quantity of phosphate on D751-Fe and D751-La was significanyly affected by p H,while a little effect of the salinity(Cl^-,SO₄^2-).Langmuir,Freundlich,Koble-Corrigan,and Redlich-Peterson models were all suitable to describe the isothermal adsorption process of phosphate.The kinetic models of Pseudo-first-order,Double constant,Elovich and Intraparticle were ideally to describe the kinetic process of phosphate adsorption on D751-Fe while the adsorption process of phosphate on D751-La was better described by Pseudo-second-order,Double constant and Elovich models.Thermodynamic parameters indicated that the adsorption process of phosphate on D751 was a spontaneous and endothermic reaction with entropy increased,while adsorption of phosphate on D751-La was regarded as a spontaneous and exothermic process with entropy reduced.The adsorption mechanism of both systems was mainly coordination.PVDF-PEI was prepared by blending PEI and PVDF and used for the removal of Cu???and Pb???from solution,respectively.The results displayed that the adsorption capacity of PVDF-PEI was significantly enhanced for removal of Cu???and Pb???from soluiton.The adsorption quantity of Cu????solution p H 5.0?and Pb????solution p H 5.2?by PVDF-PEI film were as high as 95.2 mg·g^-1,193 mg·g^-1when the solid-liquid ratio was 0.5 g·L^-1and the reaction time was 8 h.Freundlich,Koble-Corrigan,Redlich-Peterson,pseudo-first-order and Elovich model can all describe the adsorption process of Cu???and Pb???by PVDF-PEI.The thermodynamic parameters showed that the adsorption reactions of Cu???and Pb???by PVDF-PEI were both endothermic reactions with spontaneous and increased entropy.Cu-loaded PVDF-PEI can be better regenerated using 0.1 mol·L^-1HCl while Pb-loaded PVDF-PEI can be regenerated using 0.1 mol·L^-1of HNO₃.The adsorption mechanisms of Cu???and Pb???were complexation and ion exchange.