Patent ID: 6998053
Filing Date: 2006-02-14
Classification: B01D,C02F,Y02A

Abstract:
1. A desalination process using a membrane system to produce potable water which comprises: (a) passing a first stream of water containing a high concentration of hardness ions through an ion selective membrane to form softened water having a reduced content of hardness ions; (b) blending the softened water with a second stream of water containing a higher concentration of hardness ions than the softened water to form a feed; (c) passing the feed through a reverse osmosis membrane system to form a water product of potable quality, wherein the softened water content of the feed is at least 15%; and wherein the proportions of the softened water and second stream of water forming the feed are varied to increase the top operating temperature of the desalination process and increase recovery of potable water.