Selenate removal from waste water
US5009786A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 30, 1989 |
| Grant date | Apr 23, 1991 |
| Priority date | — |
| Expiry date | Oct 30, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/912
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A method and apparatus for removing selenate from waste water through the use of selenate respiring microorganisms under substantially anoxic conditions is described. The method includes a first zone for removing nitrate by assimilation into biomass. The first zone is maintained under aerobic conditions and is separated from a second zone where selenate is respired to elemental selenium by selenate respiring microorganisms under anoxic conditions. Biomass produced in the first zone may be processed to provide nutrients and electron acceptors for the maintenance of selenate respiring microorganisms when selenate becomes growth limiting. An optional sulfate reduction zone is provided in the method and apparatus where hydrogen sulfide is produced. The hydrogen sulfide so produced is circulated to the second zone and may be used to reduce residual selenite to elemental selenium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.