Process for dewatering sewage sludge
US4038181A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 23, 1976 |
| Grant date | Jul 26, 1977 |
| Priority date | — |
| Expiry date | Mar 23, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F11/12
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A process for dewatering sewage sludge having a water content on the order of 75% to 95% and previously untreated for the release of such water. The sludge is mixed with a chemical selected from the group consisting of urea and the common ammonium and potassium salts in relative quantities which produce a desired degree of phase separation. The hygroscopic qualities of the chemical operate to remove water from the sludge to form a separate liquid phase of the chemical dissolved in water removed from the sludge, and a solid or semi-solid phase of the sludge solids with any remaining water. The phases may then easily be separated with great simplification of subsequent handling, disposal or further processing of each.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.