Study On Preparation Of Hydroxyethyl Cellulose Composite Film And Adsorption And Desorption Properties Of Pb²⁺

Polymer film can be used as an adsorbent,has simple operation,can the advantages of quick absorption and adsorption rate of heavy metals.In the face of the current situation of heavy metal wastewater pollution to the environment,posing a threat to human body and animals and plants receiving water,the preparation of hydroxyethyl cellulose composite membrane has practical significance in improving the utilization rate of adsorbent,ecological sustainable development and circular economy.Hydroxyethyl cellulose（HEC）,polyvinyl alcohol（PVA）and sodium alginate（SA）were used as raw materials to prepare Hydroxyethyl cellulose membrane（HPS）,glutaraldehyde crosslinked hydroxyethyl cellulose membrane（GPHS）and magnetic hydroxyethyl cellulose membrane（FGPHS）.Three kinds of composite membrane preparation conditions were studied and stripping absorption conditions influence on Pb²⁺stripping absorption performance,through the ad sorption kinetics and adsorption isotherm models and a variety of characterization methods to analyze adsorption mechanism.The results are as follows:（1）HEC,PVA and SA were used as raw materials to prepare HPS,the maximum adsorption capacity of Pb²⁺was 253.26mg/g.The adsorption process conformed to the quasi-second-order kinetics model and Freundlich adsorption isotherm model.The maximum desorption capacity of HPS for Pb²⁺was 108.58mg/g.After the adsorption of Pb²⁺,the surface of HPS was rough and fine adhesions were gathered,and became dense,and HPS has higher thermal stability than HEC.After HPS adsorbed Pb²⁺,a large amount of divalent lead appeared,indicating that Pb²⁺was adsorbed on HPS.（2）Glutaraldehyde（GA）were used as raw materials to prepare GPHS,and the maximum adsorption capacity of Pb²⁺was 387.90mg/g,and adsorption performance was better than the HPS.The adsorption process conforms with the quasi-second-order kinetics model and Freundlich adsorption isotherm model.The maximum desorption capacity of GPHS for Pb²⁺was 178.66mg/g.After the adsorption of Pb²⁺,particles were attached to the surface of GPHS,and C-O stretching vibration peaks appeared on the film,indicating that GA had been crosslinked successfully.The thermal stability of GPHS was lower than that of HPS.Some characteristic diffraction peaks were enhanced and became relatively sharp,and the crystallinity of GPHS increases relative to HPS.（3）Fe₃O₄ was used as magnetizer to prepare FGPHS,the maximum adsorption capacity of Pb²⁺was 549.37mg/g,and adsorption performance was better than the GPHS.The adsorption process conforms with the quasi-second-order kinetic model and Freundlich adsorption isotherm model.The maximum desorption capacity of FGPHS for Pb²⁺was 264.79mg/g.After five times of suction and desorption recycling,the adsorption amount of FGPHS for Pb²⁺was 327.01mg/g,and the initial adsorption capacity reached59.68%.After the adsorption of Pb²⁺,the surface of FGPHS was rough,and Fe-O complexed with-OH and-COO,which increased the adsorption capacity.Compared with GPHS,it has better thermal stability.The XRD patterns of FGPHS showed obvious Fe₃O₄diffraction peaks,indicating that Fe₃O₄ was successfully loaded,and FGPHS has a certain magnetic properties.