Process for removing metal-EDTA complex and free EDTA salts from mixed aqueous-organic media
US4157434A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1977 |
| Grant date | Jun 5, 1979 |
| Priority date | — |
| Expiry date | Dec 30, 1997 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G65/46
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Ethylenediaminetetraacetic acid (EDTA)-complexed heavy metals alone or together with free EDTA salts are removed from solution in a mixture comprising a solvent for a polyphenylene ether resin, an antisolvent for a polyphenylene ether resin and water, by contacting the mixture with alumina for a time at least sufficient to selectively adsorb the metal-EDTA complex and free EDTA salts and recover the mixture of solvent, antisolvent and water substantially free of the metal-EDTA complex and EDTA salts. The alumina can be regenerated to nearly its full original adsorption capacity by contacting with water at a neutral or nearly neutral pH, to give an aqueous solution of the metal-EDTA complex and free EDTA salts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.