Sewage sludge additive
US4209393A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 28, 1976 |
| Grant date | Jun 24, 1980 |
| Priority date | — |
| Expiry date | Jan 28, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W10/40
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
In a raw sewage treatment process of the type where settling tanks are used for the purpose of permitting the suspended matter in the raw sewage to be settled as well as to permit adsorption of the dissolved contaminants in the water of the sewage. The sludge, which settles down to the bottom of the settling tank is extracted, pyrolyzed and activated to form activated carbon and ash which is mixed with the sewage prior to its introduction into the settling tank, for the purposes mentioned. Because the sludge does not provide all of the activated carbon and ash required for adequate treatment of the raw sewage, it is necessary to add carbon to the process. In accordance with this invention, instead of expensive commercial carbon, coal is used to provide the carbon supplement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.