Method for purifying carbon-containing pollution and denitrifying waste water in oxygenic medium
US6254778A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 1999 |
| Grant date | Jul 3, 2001 |
| Priority date | — |
| Expiry date | Mar 2, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W10/10
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
The invention is a biological process for purifying waste water in order to produce an effluent with a low content of carbon and of oxygenated nitrogen compounds. The process includes an initial step of mixing the waste water in a biological reactor with activated sludge to denitrify the resulting mixture. Then, air is introduced into the mixture to form an anoxic sludge thereby directly oxidizing carbon present in the anoxic sludge and removing carbon therefrom, simultaneous with the denitrification. The anoxic sludge is clarified to separate it from a denitrified intermediate effluent. The clarified anoxic sludge is recycled to the biological reactor. Then, intermediate effluent is nitrified to form a nitrified liquor and a portion of the nitrified liquor is recycled into the anoxic sludge that is present in the biological reactor, thereby subjecting the anoxic sludge to oxygen present in nitrified compounds and consequently further removing carbon from the anoxic sludge, simultaneous with the denitrification. The rate of removal of carbon is controlled as a function of the flow rate/pollution characteristics of the anoxic sludge while a redox potential of the anoxic sludge is co…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.