Synthesis of aminated glycidyl methacrylate grafted rice husk and investigation of its anion-adsorption properties

摘要

In this study, we focused on the synthesis, characterization, and adsorption capacity testing of aminated glycidyl methacrylate grafted rice husk (RH-g-GMA-Am). Our goal was to obtain a high-performance surface for the adsorption of various anions. Glycidyl methacrylate grafted rice husk (RH-g-GMA) was prepared by the graft copolymerization of glycidyl methacrylate with rice husk; the product was further subjected to an amination reaction. The surface properties, sorption characteristic functional groups, isotherm and kinetic studies, pore diffusion models, and effects of the temperature and pH on the material properties were studied under batch conditions. The IR spectroscopy results show additional surface functional groups for RH-g-GMA-Am. The adsorptions of PO43- and NO3- on RH-g-GMA-Am were found to follow pseudo-second-order kinetics; this indicated a possible dominant role played by chemisorption. The rate-limiting step for mass transfer was found to be boundary layer diffusion. Furthermore, the sorption isotherms for NO3- and PO43- fit the Langmuir model. The amination of RH-g-GMA drastically increased the removal efficiency from 3 to 82% and from 6 to 93% for NO3- and PO43-, respectively. Moreover, RH-g-GMA-Am exhibited a better PO43- removal efficiency in the pH range of 4-6.5. Regeneration studies revealed that the surface of RH-g-GMA-Am could be regenerated repetitively by simple acid washing with an insignificant decrease in the active surface for consecutive adsorptions. (C) 2015 Wiley Periodicals, Inc.