One-Pot Synthesis of Magnetic Cationic Adsorbent Modified with PDDA for Organic Phosphonates Removal

Fe 3 O 4 nanoparticles coating with poly dimethyl diallyl ammonium chloride (Fe 3 O 4 /PDDA) as novel magnetic adsorbents were synthesized with chemical co-precipitation method to study the removal capacity of organic phosphonates from aqueous solution. The as-prepared magnetic absorbents were characterized for the morphology, material structure and surface properties by SEM, TEM, FT-IR, XRD, TGA and BET. HEDP was employed as a common organic phosphonate to investigate the adsorption performance. Substantial quaternary ammonium groups existing on the surface of Fe 3 O 4 /PDDA could enhance the absorption of HEDP with electrostatic attraction. In the optimum condition (4[Formula: see text]mg adsorbent dosage, 11.0 pH, 36[Formula: see text]mg/L HEDP solution and 120[Formula: see text]min adsorption time), the maximum adsorption capacity ([Formula: see text]) for HEDP could reach 254.86[Formula: see text]mg/g. The kinetic study revealed that the adsorption process followed the pseudo-second-order model. The adsorption isotherm fitted closely to the Freundlich model. The as-prepared magnetic adsorbents exhibited notable reusability in some cycles and were easily separated from the solution with the external magnetic field. These as-prepared Fe 3 O 4 /PDDA nanoparticles have the potential as an environmental-friendly adsorbent for organic phosphonates removal from waste-water.