Study On The Preparation Of Functionalized Magnetic Activated Carbon And Its Adsorption Performance

Activated carbon is an ideal precursor for carbon materials.Activated carbon is used in sewage treatment and environmental remediation because of its rich oxygen-containing functional groups,porous structure,large specific surface area,and good adsorption properties.This theory is based on activated carbon and Fe₃O₄ as a magnetic body to prepare three composite materials with superparamagnetism,which is convenient for rapid separation and recovery.In this thesis,activated carbon was used as raw material to prepare magnesium oxide functionalized magnetic activated carbon,xanthate functionalized magnetic activated carbon and polyrhodanine functionalized magnetic activated carbon.Through scanning electron microscope（SEM）,transmission electron microscope（TEM）,Fourier infrared spectroscopy（FTIR）,X-ray diffraction（XRD）,nitrogen adsorption and desorption（BET）and vibration sample magnetometer（VSM）,three composite materials Physical characterization was carried out,and its adsorption performance was also explored.The specific research content is as follows:PartⅠPreparation of magnesium oxide functionalized magnetic activated carbon（MgO-mAC）and its adsorption performance for malachite greenFirst,magnetic activated carbon（mAC）was prepared by co-precipitation method,and then magnesium oxide functionalized magnetic activated carbon（MgO-mAC）was prepared by sol-gel method.MgO-mAC has a good removal effect on malachite green（MG）.The effects of adsorbent dosage,contact time,initial concentration of MG,pH and temperature on adsorption of MG were explored.In the adsorption isotherm study,the fitting results were more consistent with the Langmuir isotherm model,and the maximum adsorption capacity of malachite green（MG）was 3809.38 mg/g.In the kinetic study,the results show that the adsorption process conforms to the pseudo-second-order kinetic model.In thermodynamic studies,the results show that the adsorption is an endothermic spontaneous process,and the amount of adsorption increases as the temperature rises.The reusability study showed that the adsorption removal rate of Mg by MgO-mAC could still reach more than 79.60%after repeated use for 5 times.In addition to strong adsorption capacity,the adsorbent also has the advantages of green synthesis,recyclability,and easy separation.PartⅡPreparation of xanthate functionalized magnetic activated carbon（x-mAC）and its adsorption performance for cationic dyes and tetracycline hydrochlorideFirst,magnetic activated carbon（mAC）was prepared by co-precipitation method,and then x-mAC functionalized magnetic activated carbon was prepared through xanthate reaction（x-mAC）.x-mAC is used to remove malachite green（MG）,methylene blue（MB）,crystal violet（CV）and tetracycline hydrochloride（TC）.In the isotherm adsorption model study,the fitting results are more in line with the Langmuir isotherm model.The maximum adsorption capacities of malachite green（MG）,methylene blue（MB）,crystal violet（CV）and tetracycline hydrochloride（TC）are 636.94 mg/g,338.98 mg/g,403.23 mg/g and 221.73 mg/g,respectively.Kinetic studies have shown that the adsorption process of the four pollutants is more in line with the pseudo-second-order kinetic model.In the thermodynamic study,the results show that the adsorption process endotherms spontaneously,the adsorption amount increases with the increase of temperature,and the degree of disorder in the adsorption process increases.After five cycles,the removal rates of MG,MB,CV and TC remained above 91.86%,93.87%,81.25%and 92.00%,respectively.PartⅢPreparation of polyrhodanine functionalized magnetic activated carbon（PR-mAC）and its adsorption performance for lead ions and malachite greenFirstly,magnetic activated carbon（mAC）was prepared by co-precipitation method,and then polyrhodanine functionalized magnetic activated carbon（PR-mAC）was prepared by in-situ reduction method.PR-mAC is used to remove lead ions（Pb（Ⅱ））and malachite green（MG）.In the study of adsorption isotherms,the Langmuir isotherm model can better describe the adsorption process.The maximum adsorption capacities of Pb（Ⅱ）and MG are 223.46mg/g and 315.71 mg/g,respectively.In the kinetic study,the fitting results show that the adsorption process conforms to the pseudo-second-order kinetic model.In the thermodynamic study,the results show that the absorption process takes place spontaneously.Reusability studies show that the removal rate of Pb（Ⅱ）and MG by PR-mAC can still reach 75.90%and86.60%after repeated use for 5 times.