Magnetic bentonite composite: Synthesis, characterization and preliminary adsorption-desorption study towards removal of methylene blue.

For the past five years, application of magnetic adsorbent for the remediation of textile effluent is receiving significant attention due to its low cost, simple preparation, and easy recovery. In this study, a magnetic bentonite composite (MBC) was synthesized through co-precipitation technique and then used for removing Methylene Blue (MB) dye. The raw bentonite and MBC were characterized using vibrating-sample magnetometry (VSM), X-ray powder diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. The FTIR analysis indicated the possible involvement of hydrogen bonding between the iron oxide and bentonite particles to form the MBC. The magnetic composite exhibited a saturation magnetization of 9.2 emu/g with high degree of crystallinity as displayed in the XRD pattern. During a preliminary adsorption study, the MBC successfully removed 100% MB from aqueous solution with a maximum adsorption capacity of 100 mg/g. Immersion of spent MBC in various desorption eluent (1 M of NaOH, NaCl, HNO3, EDTA, and deionized water) showed a negligible MB desorption. This composite exhibits great potential as a green and efficient adsorbent for future works involving dye remediation. [ABSTRACT FROM AUTHOR]