Development of Mag-FMBO in clay-reinforced KGM aerogels for arsenite removal

To seek high-efficient, convenient and robust methods to decontaminate water polluted by arsenite are critically in demand. Here, we developed a series of magnetic konjac glucomannan (KGM) aerogels as adsorbents for arsenite removal. These adsorbents were fabricated based on sodium montmorillonite (Na+-MMT) reinforced KGM matrix with magnetic Fe and Mn oxides (Mag-FMBO) inside. The obtained aerogels adsorbents were characterized by using compression test, thermo gravimetric analysis (TGA), vibrating sample magnetometer (VSM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The characteristic results showed that the composite aerogels possessed strong mechanical and magnetic property, excellent thermal characteristic and tunable pore structure. Batch adsorption tests were used to evaluate arsenite removal capacity. The adsorption results exhibited that the arsenite removal process was pH-dependent, followed a pseudo-second-order rate equation and Langmuir monolayer adsorption. The maximum arsenite uptake capacity of magnetic aerogels M1.5 reached 16.03 mg g−1 according to Langmuir isotherm at pH 7 and 323 K. Besides, the magnetic composite aerogels can be repeatedly used after the treatment of regenerant (NaOH/NaCl/NaClO solution).

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