Treatment of biologically-degradable waste
US4416781A · kind A · utility
11Cited by
11References
22Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 14, 1982 |
| Grant date | Nov 22, 1983 |
| Priority date | — |
| Expiry date | Jun 14, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W10/10
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for the secondary treatment of sewage (and apparatus therefor) having a step in which sewage is circulated in a system having a riser and a downcomer communicating with each other at their upper and lower ends and in which an oxygen-containing gas is supplied to the sewage as it passes through the downcomer. The method is intended for use in the aeration and/or digestion steps of the secondary treatment of sewage. The riser and downcomer are preferably located in a shaft extending into the ground for at least 40 meters below a basin containing the sewage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.