Fabrication Of Three Types Of Sodium Alginate Composite Materials For Heavy Metal Ions Adsorption

Heavy metal ions often remain in water and grocery are a seriously threaten human health,so it is of great significance to study the removal of heavy metal ions.In this paper,three kinds of complex gel adsorbents were prepared based on sodium alginate,a natural marine polymer,and their adsorption properties of Pb???and As???were studied respectively.The research results are as follows:?1?ZIF-8@CA composite gel adsorption material was prepared by combining sodium alginate?SA?with metal organic framework?MOF?material ZIF-8 at room temperature.The adsorption materials were characterized by scanning electron microscopy?SEM?,Infrared spectroscopy?IR?,X-ray photoelectron spectroscopy?XPS?and X-ray diffraction?XRD?.The performance of Pb???adsorbed by ZIF-8@CA was studied experimentally.The results showed that the optimum adsorption conditions:the temperature was25?,the pH value of 5,the adsorption equilibrium time was 120 min,and the maximum adsorption capacity was 1321.21 mg/g.The adsorption process conforms to Langmuir isotherm model and quasi-second order kinetic model.?2?The hydrothermally obtained ASBA-15 was mixed with a sodium SA,and then crosslinked with CaCl₂ to prepare Sodium alginate/aminated mesoporous molecular sieve?ASBA-15@CA?.The adsorbents were characterized by IR,SEM,thermogravimetric analysis?TGA?,XRD,XPS and N₂adsorption-analytical analysis?BET?.The performance of Pb???adsorbed by ASBA-15@CA was studied experimentally.The effects of different adsorption factors on the adsorption process were investigated.The results showed that the optimum adsorption conditions:the temperature was 25?,the pH value of 6,the adsorption equilibrium time was 100 min.The maximum adsorption capacity was1068.38 mg/g,and the removal rate could reach 99.23%.The adsorption progress conforms to the Langumir isotherm model and follows a quasi-second kinetics model.?3?MT?Al?@CA microspheres were prepared by complexing SA and aluminum pillared montmorillonite[MT?Al?],and then the microspheres were further modified with ethylenediamine?ED?to obtain a core-shell new adsorbent MT?Al?@CA-ED.The adsorbent was characterized by SEM,IR,XRD and XPS.The adsorption performance of aminated sodium alginate/aluminum pillared montmorillonite[MT?Al?@CA-ED]on As???in solution was studied.The results showed that at pH 4,the removal rate of As???by MT?Al?@CA-ED after 150min could reach 94.85%.The adsorption progress was in line with the Langmuir isotherm model?R²=0.9983?and the quasi-second-order kinetic model?R²=0.9973?...