Removal of boron from SWRO permeate by boron selective ion exchange resins containing N-methyl glucamine groups

The objective of this study is to explore the performance of the boron selective ion exchange resins for boron removal from seawater reverse osmosis (SWRO) permeate. A lab-scale cross-flow flat-sheet configuration test unit (SEPA CF II, Osmonics) and FilmTec RO membranes were used for batch-mode RO tests. Seawater samples containing 5.1 mg B/L were collected from the Mediterranean Sea. The chelating ion exchange resins containing N-methyl glucamine groups (Diaion CRB 02 and Dowex-XUS 43594.00 resins) were employed for batch and column-mode tests to remove boron from SWRO permeate. Optimum resin amount for boron removal from SWRO permeate was found as 1 g resin/L for both Diaion and Dowex resins. The equilibrium half-time for B removal was between 30 and 45 min for Dowex and 20–30 min for Diaion resins. Sorption kinetics for these resins fit to Ho pseudo-second-order kinetics model. Both resins exhibited large breakthrough capacities with boron leakage of less than 0.2 mg B/L. Breakthrough capacity was influenced by space velocity. Boron loaded onto the resins was quantitatively eluted with 5% H2SO4 solution.