Study On The Properties Of Phenolic Amine Composites And Their Adsorption Of Heavy Metal Ions

Based on the study of polyphenolamine reaction and the application of adsorbability,the polyphenolamine chelating resin and its composite were designed and synthetized in this paper,including catechol-cysteamine resin?PCCA?,catechol-butylenediamine resin@Fe₃O₄?Fe₃O₄@PCBA?composite,amines of silica based poly?catechol-tetraethylenepentamine?composites?SiO₂-APTS@PCaTpa?.These materials were applied to adsorb the Cr?VI?in solution,whose morphologies and structures were characted by transmission electron microscope?TEM?,the environmental scanning electron microscopy?SEM?,Fourier transform infrared?FT-IR?,thermogravimetric analysis?TGA?,X-ray photoelectron spectroscopy?XPS?,energy dispersive spectroscopy?EDS?,etc.The exploration of various factors affected to adsorption capacities of adsorbents,which contain pH value,time,temperature,initial concentration and so on,was investigated.Furthermore,the obtained data were fitting with the adsorption isothermal models,kinetic equations and thermodynamic equations respectively and the adsorption mechanisms were also studied.This article was mainly divided into three parts:?1?Study on the adsorption of Cr?VI?from aqueous solution by the Fe₃O₄@PCBA composite material.Fe₃O₄@PCBA adsorption experiments on Cr?VI?showed that the adsorption equilibrium time was 48 h,and the maximum removal amount was 280.11 mg/g at293 K.The process was spontaneous and endothermic,which accords with Langmuir and pseudo two order kinetics equation.When the adsorption capacity is 250 mg/g,Cr?VI?can almost be removed safely.Therefore,the Fe₃O₄@PCBA composite particles can directly remove Cr?VI?in the solution.?2?the study on the adsorption of Cr?VI?in the solution by PCCA.Cysteamine monomer and catechol were used to prepare PCCA and used to adsorb Cr?VI?in solution.The kinetic calculation shows that the removal ability of the adsorbent for Cr?VI?is in accordance with the quasi two stage kinetics,the maximum removal amount is 342.8 mg/g,and the Cr?VI?can be removed safely under the condition of maintaining the adsorption capacity of 300mg/g,so PCCA can directly remove the Cr?VI?in the solution and analyze the adsorption mechanism.Thermodynamic parameters indicate that the process is endothermic and spontaneous.After adsorption for three times,the adsorbent still maintains a high adsorption capacity for Cr?VI?.?3?comparison of the removal capacity of Cr?VI?by SiO₂-APTS@PCaTpa composites:SiO₂-APTS@PCaTpa composites were synthesized in different phenolic amine ratios,and Cr?VI?was adsorbed under the same condition.The isothermal model,kinetic model and thermodynamics were studied in turn.All of them were found to be in accordance with Langmuir and quasi two kinetics equations,and Cr?VI?was at the same time.The adsorption will be reduced to Cr?III?at the same time,and its maximum adsorption capacity is 400 mg/g,which can almost safely remove Cr?VI?under the condition of maintaining the adsorption capacity of 350 mg/g,so the chelating resin can directly remove Cr?VI?in the solution.To sum up,polyphenol amine chelating resin is rich in raw materials,low in cost,simple in preparation and large in adsorption,especially under the low concentration of Cr?VI?ion,which can maintain high quantity and removal rate,and easily regulate molecular structure and further modification.In conclusion,polyphenol amine adsorption material has good application prospects and research value in the treatment of sewage.