Water treatment process
First Claim
1. A process for softening water comprising the steps of(a) passing a first stream of water through an anion-exchange unit to raise the pH of said first stream and provide a second stream of water having a pH of at least 9.5, said anion-exchange unit being a unit adapted to release hydroxyl ions;
- (b) providing said second stream of water to water softening equipment comprising reactor and clarifier sections, said second stream of water being used as the principal source of hydroxyl ions in said water softening equipment;
(c) processing a fourth stream of water through said water softening equipment, said fourth stream comprising said second stream; and
(d) operating said water softening equipment on said fourth stream of water to remove via precipitation reactions hardness ions from said fourth stream and to provide thereby a fifth stream of water.
1 Assignment
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Accused Products
Abstract
An improved water softening process is provided which also reduces anion content. A first stream of water is passed through an anion-exchange unit to remove undesirable anions and raise the pH. The first stream of water is then provided to reactor/clarifier water softening equipment, where it acts as a source of hydroxyl ions. Preferably a second stream of water which did not pass through an anion-exchange unit is also provided to the water softening equipment. The streams of water are combined and processed through the softening equipment, where hardness ions are precipitated out, yielding softened water with reduced anion content. The anion-exchange system utilized preferably has a counter-current continuous resin train and a counter-current continuous resin regeneration unit.
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Citations
34 Claims
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1. A process for softening water comprising the steps of
(a) passing a first stream of water through an anion-exchange unit to raise the pH of said first stream and provide a second stream of water having a pH of at least 9.5, said anion-exchange unit being a unit adapted to release hydroxyl ions; -
(b) providing said second stream of water to water softening equipment comprising reactor and clarifier sections, said second stream of water being used as the principal source of hydroxyl ions in said water softening equipment; (c) processing a fourth stream of water through said water softening equipment, said fourth stream comprising said second stream; and (d) operating said water softening equipment on said fourth stream of water to remove via precipitation reactions hardness ions from said fourth stream and to provide thereby a fifth stream of water. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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Specification