Sewage-water purifying process
US4732679A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 11, 1986 |
| Grant date | Mar 22, 1988 |
| Priority date | — |
| Expiry date | Sep 11, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/903
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A water purifying method, particularly a sewage purification method, for eliminating nitrogen therefrom, in which (a) the water is subjected to a preprecipitation process with the aid of trivalent and/or multivalent metal salts for prereduction of incoming contaminants; (b) the NO.sub.3 present is reduced to nitrogen gas by anaerobic fermentation, in which readily decomposed organic material serves as the carbon source and gives by preprecipitation according to (a) an optimum nitrogen reduction in respect of each sewage category; (c) the ingoing ammonium nitrogen is oxidized to nitrate by aerobic fermentation while simultaneously blowing-off nitrogen-gas bound to the water, wherein water (sewage) that contains nitrate is passed to the reduction stage (b) and bacteria-containing sludge is passed from the aerobic stage to the anaerobic stage, and wherein process stages (b) and (c) can be carried out in any desired order subsequent to step (a).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.