Accelerated removal of nitrate from aqueous solution by utilizing polyacrylic anion exchange resin with magnetic separation performance

In order to quickly remove nitrate from aqueous solution, a magnetic strong base quaternary ammonium anion exchange resin (MAER) has been successfully designed and synthesized. The physicochemical properties of the MAER as well as its adsorption ones for nitrate removal were investigated in detail. A series of batch experiments were carried out to evaluate the effects of several factors on removal efficiency of nitrate, such as retention time, resin amount and initial nitrate concentration. Compared to the commercial Purolite A300 and D213, the equilibrium time for the adsorption process using MAER was only around 20 min, which is significantly less than that of two ones mentioned. Furthermore, the kinetic process of nitrate sorption on MAER could be well described by both pseudo-first-order and pseudo-second-order models. In addition, the results of batch experiments can be better fitted by the Langmuir and Freundlich adsorption isotherm models. Most importantly, the effects of competing ions on nitrate removal followed the order as: SO42− > Cl− > HCO3−. These results are of significance in guiding the development of novel resins with the rapid nitrate removal rate from aqueous solution, which would improve efficiency and save energy greatly.