Process of dewatering sewage sludge
US4038180A · kind A · utility
26Cited by
5References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 9, 1976 |
| Grant date | Jul 26, 1977 |
| Priority date | — |
| Expiry date | Jan 9, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F11/13
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Sludge from a municipal or industrial sewage treatment facility is mixed with a mineral acid or anhydride thereof to release the entrapped water in the sludge. The remaining mixture of sludge solids and diluted acid or anhydride is then mixed with a basic material, such as ammonia, the heat generated by reaction of the base and acid evaporates the water to form either a completely dry mixture of sludge solids and a salt, or a mixture having a predetermined moisture content which may be air dried. In some applications it is preferable to recycle a portion of the end product by adding it to the reaction vessel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.