A submerged membrane–ion-exchange hybrid process for boron removal

The studies focused on evaluation of a sorption membrane hybrid process using N-methyl glucamine chelating resins for boron sorption and submerged microfiltration membrane for removal of resin-boron complexes. Hollowfiber polypropylene membranes with 0.4 μm pores were used as filtration material. Boron sorption kinetics were determined for two kinds of resins: ground Diaion CRB02 (Mitsubishi) and Dowex XUS 43594.00 (Dow Chemical). The first resin sorbed boron much faster that the latter: the Diaion resin needed 5 min while the Dowex resin took 30 min to decrease the boron concentration to half the initial concentration. For the tests carried out in the sorption–membrane system, it was shown that the process reached its steady-state condition after 1 h.