Polyamide membranes useful for water softening
US4765897A · kind A · utility
72Cited by
9References
31Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1986 |
| Grant date | Aug 23, 1988 |
| Priority date | — |
| Expiry date | Apr 28, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/3175
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A novel water softening membrane and process for making the same is described. The membrane can be prepared by treating a polyamide reverse osmosis membrane with a strong mineral acid followed by treatment with a rejection enhancing agent. The resulting membrane at transmembrane pressures of 50 psi can attain a magnesium sulfate rejection with a 0.2 percent aqueous solution of more than 90 percent with a water flux of more than 15 gallons per square foot per day.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.