Process for separating and recovering an anionic dye from an aqueous solution
US5707525A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 5, 1996 |
| Grant date | Jan 13, 1998 |
| Priority date | — |
| Expiry date | Jun 5, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J20/3278
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A solid/liquid phase process for the separation and recovery of an anionic dye from an aqueous solution is disclosed. The solid phase comprises separation particles having surface-bonded poly(ethylene glycol) groups, whereas the aqueous solution from which the anionic dye molecules are separated contains a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved lyotropic salt. After contact between the aqueous solution and separation particles, the anionic dye is bound to the particles. The bound anionic dye molecules are freed from the separation particles by contacting the anionic dye-bound particles with an aqueous solution that does not contain a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved lyotropic salt to form an aqueous anionic dye solution whose anionic dye concentration is preferably higher than that of the initial dye-containing solution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.