Comparison of ion exchange resins used in reduction of boron in desalinated water for human consumption

There are currently different resins on the market used for the elimination of boron in water. They are composed of the same active group. These are crosslinked macroporous polystyrene resins, with the active group N-methyl-D-glucamine (NMG). The NMG of the resin captures the boron via a covalent bond. The borate ion is complexed by two sorbitol groups. A comparative study of the resins Amberlite IRA 743, Purolite S-108 and XU-43594.00 Filmtec was carried out in a pilot plant of 160 L/h. The retention capacity of boron and its performance compared with other ions was analyzed. The water used as feed comes from the desalination plant of Alicante Canal. The behaviour of the three resins is very similar and the beginning of the appearance of boron in the treated water in all three cases occurred at virtually the same point. To check the selectivity of the resin for boron, the main cations in water, sodium, potassium, calcium and magnesium were analyzed. No reduction in the concentration of the cations tested was observed in any of the resins. The only change experienced by the treated water through the resin was a reduction in the boron concentration. ► This paper examines comparatively the effectiveness of different resins used in the removal of boron from water previously desalted by reverse osmosis. ► The selectivity of the same with respect to boron is also tested by not removing other ions in the solution. ► The fundamental difference with previous work published is that we have worked on a pilot scale and not in the laboratory. ► Feed water that we used was desalinated water of a seawater reverse osmosis plant and we worked continuously, in real conditions of operation.