A spherical N-methyl-d-glucamine-based hybrid adsorbent for highly efficient adsorption of boric acid from water

Preparation of a novel hybrid boron-selective adsorbent with N-methyl-d-glucamine functional groups was reported. The adsorbent was synthesized by inverse suspension polymerization method based on chemistry of sol-gel reaction. The structure and morphology of the hybrid adsorbent were characterized by MS, FTIR, XPS, BET analysis and PXRD, etc. The perfectly spherical hybrid adsorbent exhibits exceptionally efficient adsorption of boric acid from the aqueous solution. The boron adsorption behavior on the adsorbent was investigated by varying the dosages of the adsorbent, pH, and competitive ions. The adsorption isotherm was in better accordance with the Langmuir model, exhibiting a theoretical maximum adsorption capacity of 2.02 mmol/g. The adsorption capacity peaks at pH ∼ 9 due to the vast formation of stable tetrahedral structure between dominant B(OH)4− and the adsorbent. The presence of Na+ ions has slight effect on boron adsorption while Mg2+ cations significantly enhanced the adsorption capacity because of the simultaneous adsorption attributed by Mg(OH)2.