Patent ID: 8980101
Filing Date: 2015-03-17
Classification: C02F

Abstract:
1. A method of inhibiting scale formation and deposition from an iron-containing [Fe 3+ ] feed stream passing through a reverse osmosis system, the method consisting essentially of: controlling the pH of said feed stream within the range between about 7.5 and about 8.2; controlling the temperature of said feed stream within the range between about 5° C. to about 40° C.; and adding an effective amount of a scale inhibitor to said feed stream, said scale inhibitor consisting of an acrylic acid—2-acrylamido, 2-methyl propyl sulfonic acid copolymer having a weight average molecular weight of about 1000 to about 100,000 daltons and a molar ratio of acrylic acid to 2-acrylamido, 2-methyl propyl sulfonic acid of 80:20; wherein the reverse osmosis system has a first stage and a second stage, wherein a concentrate stream from the first stage feeds the second stage; and wherein the effective amount of scale inhibitor is determined based upon stable turbidity measurements of said feed stream and/or a reject stream of the reverse osmosis system.