Author(s)

Adebola Abosede Adeyi¹, Toluwalope Gbemileke Abayomi^1,2*, Mihir Kumar Purkait³, Piyal Mondal³

¹Departmenet of Chemistry, University of Ibadan, Ibadan, Nigeria.
²Department of Chemical Science, Adekunle Ajasin University, Akungba Akoko, Nigeria.
³Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, India.

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.

Magnetite, Kaolin, Phosphate, Adsorption

Adeyi, A. , Abayomi, T. , Purkait, M. and Mondal, P. (2019) Adsorptive Removal of Phosphate from Aqueous Solution by Magnetic-Supported Kaolinite: Characteristics, Isotherm and Kinetic Studies. Open Journal of Applied Sciences, 9, 544-563. doi: 10.4236/ojapps.2019.97043.