Ammonia Adsorption Property of Fibrous PP-g-GMA-SO3H Adsorbent Prepared by Photoinduced Graft Polymerization and Subsequent Sulfonation

PP-g-GMA-SO₃H adsorbent, which possesses a cation-exchange functionality, was synthesized by the photoinduced grafting of glycidyl methacrylate (GMA) onto polypropylene (PP) non-woven fabric, followed by a sulfonation reaction using sodium sulfite. The adsorption properties of the PP-g-GMA-SO₃H adsorbent for ammonia ions were studied in batch mode. The adsorption equilibria of NH₃-N on PP-g-GMA-SO₃H were well described by the Langmuir isotherm model, with a maximum adsorption capacity of 31.6-37.5 mg/g. The adsorption energies calculated from the D-R model and Temkin model ranged between 10.8-13.5 kJ/mol, indicating that an ion-exchange process was involved. Adsorption kinetic data fitted the pseudo-second-order kinetic model, indicating that both external and intraparticle diffusion played roles in the adsorption processes. The PP-g-GMA-SO₃H adsorbent could be regenerated by washing with 0.1 M HCl without significantly lowering the adsorption capacity.