Sorption of trace levels of bromate by macroporous strong base anion exchange resin: Influencing factors, equilibrium isotherms and thermodynamic studies

Bromate, a cancerigenic disinfection by-product (DBP), has been increasingly concerned in recent years. In this study, macroporous Cl-type strong base anion exchange resin (D201-Cl) was used to remove trace levels of bromate from aqueous solution. Batch sorption experiments were performed to evaluate the influence of various factors such as initial bromate concentration, contact time, solution initial pH and temperature on the uptake of bromate. D201-Cl resin exhibited higher bromate removal efficiency (residual concentration of bromate was under the maximum contaminant level (MCL) of 10 μg·L− 1 at all conditions investigated) and broader pH scope of application (4.50-9.92). The maximum sorption capacity reached to 105.5 mg·g− 1 at 298 K. The kinetics data were well described by pseudo-first-order kinetic model, and Freundlich isotherm model and Redlich-Peterson isotherm model fitted the sorption isotherms (R2 > 0.99). Thermodynamic analysis showed that the sorption process was spontaneous and endothermic. In addition, D201-Cl resin still maintained high bromate removal efficiency after regenerated by 0.1 M NaCl solution for five cycles. The results indicate that D201-Cl resin is a low-cost and efficient sorbent for bromate removal from drinking water, especially for trace levels of bromate.