Method for inhibiting scale formation and/or dispersing iron in reverse osmosis systems
US5358640A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 16, 1993 |
| Grant date | Oct 25, 1994 |
| Priority date | — |
| Expiry date | Sep 16, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02A20/131
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for inhibiting calcium sulfate scale formation and deposition and/or dispersing iron from a feedstream passing through a reverse osmosis system which comprises the steps of: controlling the pH of the feedstream within the range between about 6.0 to about 7.0; controlling the temperature of the feedstream within the range between about 50.degree. to about 80.degree. F.; and adding a scale inhibitor and/or iron dispersant to the feedstream in an amount between about 0.002 ppm per ppm hardness (as CaCO.sub.3) of the feedstream to about 0.005 ppm per ppm hardness (as CaCO.sub.3) of the feedstream, the scale inhibitor comprising a water-soluble organic phosphonate, an N-substituted acrylamide polymer, caustic and water.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.