Water conditioning process
AssigneeRohm and Haas Company
InventorRobert Kunin
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Abstract
Water is conditioned by contacting it with a weak acid cation exchange resin based upon a crosslinked methacrylic acid copolymer structure in the alkali metal (or ammonium) form. The resin when exhausted may be regenerated by either a two-step acid/alkali technique or by a one-step technique using a citric or fumaric acid solution or a poly or hexamethaphosphate solution. Water by this method is substantially free of hardness ion, dissolved heavy metal ions and has a corrected pH between 7 and 9.5, preferably between 8 and 8.5.
Claims7
A water conditioning process for treating acid water in order to remove therefrom hardness ions, dissolved heavy metals, and to correct the pH of the water to within a range of 7-9.5, which process comprises contacting the water with a weak acid cation exchange resin which has been regenerated to 70-96% of its salt form, the resin comprising a crosslinked methacrylic acid copolymer in the alkali metal or ammonium form wherein the crosslinking monomer is present in an amount of 2.5-10% by weight.
Dependencies are inferred from the claim text.