Preparation,Characterization And Adsorption Properties Of Biomass Lignin-based Adsorbent

With the rapid development of industry,the shortage of natural resources and the pollution of natural environment has become a serious problem.The problem of dye and heavy metal ion wastewater makes the crisis of water resources more serious.In this paper,three kinds of adsorbents?aminated calcium lignosulfonate?ACLS?,carbon composite lignin based adsorbent?C-ACLS?,magnetic lignin-based adsorbent?Fe₃O₄/C-ACLS??were prepared by amination modification of calcium lignosulfonate?CLS?with inorganic carbon material and magnetic material based on calcium lignosulfonate.The details are as follows:?1?In the presence of the cross-linker glutaraldehyde,Calcium lignosulfonate adsorbent ACLS was prepared by the modification of calcium lignosulfonate with triethylenetetramine.The adsorbent was characterized by scanning electron microscopy?SEM?,thermogravimetric analysis?TGA?and Fourier transform infrared spectroscopy?FT-IR?.And the efficiency of ACLS for the removal of Congo red and the Titan yellow dyes was evaluated by several factors,such as temperature,pH,adsorbent dose,contact time and initial concentration of dyes solution.The adsorption results demonstrated a good ability to remove dye with the removal rates of 97%and91%for 30 mg L^-11 Congo red and 40 mg L^-11 Titan yellow,respectively.The adsorption ability of heavy metal ions of Cu²⁺?Co²⁺?Ni²⁺?Zn²⁺?Pb²⁺?Cd²⁺adsorbent was tested.It was found that ACLS could adsorb heavy metal ions in the solution.This indicates that ACLS has the potential to treat wastewater.?2?Carboncompositelignin-basedadsorbentwerepreparedthrough hydrothermal method with glucose as carbon source,calcium lignosulfonate?CLS?and triethylene tetramine as raw materials,respectively.The samples were characterized by SEM,FT-IR,TGA,X ray powder diffraction?XRD?,Raman spectroscopy and elemental analysis.The adsorbent was used for the adsorption of azo dyes Congo red and Eriochrome blue black R and the adsorption of heavy metal ions,and the five factors affecting the adsorption were discussed,the corresponding adsorption mechanism such as pseudo first order kinetics,pseudo second order kinetics,intraparticle diffusion,Langmuir adsorption isotherm,Freundlich isotherm,Temkin isotherm,Dubinin-Radushkevich?D-R?adsorption isotherm,thermodynamics were also studied.Congo red and Eriochrome blue black dyes removal rate have reached 99%in the dye concentration of 40 mg L^-11 through the study of adsorption.The removal rate of Pb²⁺,which has the best adsorption effect,has reached 83%.?3?First,magnetic Fe₃O₄ with good magnetic properties was prepared by solvothermal method.Then,the magnetic Fe₃O₄ is coated with a layer of organic carbon derived from the hydrothermal carbonization of glucose to form a carbon-coated magnetic Fe₃O₄/C,and then magnetic material was combined with calcium lignosulfonate to prepared of green recyclable magnetic lignin based adsorbent Fe₃O₄/C-ACLS.The samples were determined and characterized by FT-IR,SEM,TGA,XRD,vibrational sample magnetometer?VSM?,Raman spectroscopy,elemental analysis,and applied to the adsorption of Congo red,Titan yellow,Eriochrome blue black R and heavy metal ions.The results of dye adsorption showed that the removal rates of Congo red,Titan yellow,Eriochrome blue black R were 87%,84%and 88%respectively after 5 cycles of adsorption regeneration.The performance test of heavy metal ions showed that the highest removal rate was 89%.