摘要
Natural kaolin (NK) and magnetite-modified kaolin (MK) prepared by co-precipitation were used as adsorbents to remove phosphate from aqueous solution. The materials were characterized using X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscope (FESEM), and vibrating sample magnetometer (VSM). Batch adsorption experiment was carried out to determine the phosphate removal efficiencies of these materials. The magnetic-supported kaolin showed better dispersion and less co-aggregation which ensured better fusion of the kaolin with magnetite (Fe3O4). The removal process of phosphate was governed by physico-chemical process. The results demonstrated that the adsorption of phosphate onto NK and MK was highly pH-dependent and the kinetics of the adsorption followed pseudo-second order equation. The adsorption data of Mk adsorbent fitted better with the Freundlich isotherm equation. The MK showed much better adsorption capacity per mass of MK (52.91 mg/g) than untreated NK (17.61 mg/g). Since the magnetic kaolin can be easily prepared, it enables promising application for the removal of phosphate from aqueous solution. Hence, this new class of efficient adsorbent (MK), can have a variety of application in industrial processes.
Natural kaolin (NK) and magnetite-modified kaolin (MK) prepared by co-precipitation were used as adsorbents to remove phosphate from aqueous solution. The materials were characterized using X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscope (FESEM), and vibrating sample magnetometer (VSM). Batch adsorption experiment was carried out to determine the phosphate removal efficiencies of these materials. The magnetic-supported kaolin showed better dispersion and less co-aggregation which ensured better fusion of the kaolin with magnetite (Fe3O4). The removal process of phosphate was governed by physico-chemical process. The results demonstrated that the adsorption of phosphate onto NK and MK was highly pH-dependent and the kinetics of the adsorption followed pseudo-second order equation. The adsorption data of Mk adsorbent fitted better with the Freundlich isotherm equation. The MK showed much better adsorption capacity per mass of MK (52.91 mg/g) than untreated NK (17.61 mg/g). Since the magnetic kaolin can be easily prepared, it enables promising application for the removal of phosphate from aqueous solution. Hence, this new class of efficient adsorbent (MK), can have a variety of application in industrial processes.
