Optimization of boron removal in old and new SWRO systems

Abstract

It is well known that boron rejection of RO membranes from seawater at low and natural pH is limited. This obstacle was not observed before statutory standards of drinking water limiting boron content were enforced. The awareness of the boron problem arose in Israel following the operation of the first SWRO plant in 1997 in Eilat. The farmers using the reclaimed wastewater detected partial poisoning of some crops. After identifying the boron as the toxin, Mekorot initiated a comprehensive investigation of all possible steps to reduce the boron content in the desalts seawater. The studies were performed in cooperation with a European consortium in the framework of the Joule 5 research program — BOREMED — “Boron contamination of water resources in the Mediterranean region: distribution, sources, social impact and remediation”. This is a 3-year research program (began in February 2001). In the framework of this program a new technology for boron elimination is being developed to be field tested in Cyprus and in Israel (by Mekorot). Details of the optimization program including case studies of boron reduction in old and new systems are presented.