Boron removal from seawater reverse osmosis permeate utilizing selective ion exchange resin

• Published in: Desalination 1999-11, Vol.124 (1), p.131-135
• Main Author: Nadav, Nissim
• Format: Article
• Language: English
• Subjects: Applied sciences; Boron; Drinking water and swimming-pool water. Desalination; Exact sciences and technology; Marine; Pollution; Red Sea; Selective ion exchange resin; Water treatment and pollution
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/S0011-9164(99)00097-1

A minimum of boron in irrigation water is required for certain metabolic activities, but if its concentration is only slightly higher, plant growth will exhibit effects of boron poisoning, which are yellowish spots on the leaves and fruits, accelerated decay and ultimately plant expiration. Seawater in general contains relatively high concentration of boron: 4 to 5 ppm. The Red Sea water utilized as feed for the Eilat desalination plant contains 4.7 ppm boron falling within the above range. When acidified as a part of pre-treatment, the boron is in the form of boric acid, manifesting poor trans-membrane rejection of 65%. In the Eilat desalination plant the result has been 1.8 ppm of boron concentration in the permeate, a level by far higher than the allowance of the standards. A process based on the selective removal of boron with resin has been evolved. The pilot plant tests allowed an accurate cost assessment for the removal of boron in the range of 4 to 6 US cents per cubic meter of permeate, dependent on the cost of the resin, the chemicals, and the operation and maintenance.