Rapid reduction of aqueous selenate with chromous ions
US11958764B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 23, 2022 |
| Grant date | Apr 16, 2024 |
| Priority date | — |
| Expiry date | May 23, 2042 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2303/18
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Processes are provided for the kinetically efficient reduction of selenate species to selenide species using chromous ions in acidic solution. This reduction may advantageously be carried out in the presence of sulphate species, with selective selenate reduction in preference to the reduction of sulfate. The reduced selenate may be removed from the chromous-treated solution, for example by precipitation of a copper-selenide solid. The chromic ions formed by reaction of chromous ions in the reduction of selenate may also be removed from solution, for example by addition of a base to form an insoluble chromic hydroxide solid. The chromic hydroxide may be recycled to regenerate chromous ions, for example by electrolysis. In this way, systems are provided for continuously removing dissolved selenium from wastewater streams.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.