Spent brine reclamation
US6004464A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 14, 1998 |
| Grant date | Dec 21, 1999 |
| Priority date | — |
| Expiry date | Jul 14, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J49/50
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method of reclaiming spent aqueous brine solutions used in the regeneration of water-softening resins. An aqueous solution chloride or other brine is acidified with HCl to a pH of between about 0.5 and 6 and a soluble sulfate salt, preferably Na.sub.2 SO.sub.4 is added, together with a precipitation inhibitor of the type polyacrylamide. Following such treatment, the spent brine is pumped at high pressure axially through a spirally-wound nanofiltration-type membrane device which is effective to remove at least about 90% of the divalent hardness while allowing passage therethrough of at least about 90% of the monovalent cations. As a result of such treatment, about 90 to 95% of the volume of spent brine can be efficiently and effectively reclaimed in a form in which it is suitable for use again in regenerating water-softening resins or the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.