Method of dewatering sludge and the sludge thus dewatered
US7628925B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 8, 2004 |
| Grant date | Dec 8, 2009 |
| Priority date | — |
| Expiry date | Nov 19, 2025 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F1/54
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
The invention concerns a method for dehydrating sludge, comprising adding a basic agent to sludge having a pH not more than 8, adding to the sludge at least one organic flocculating constituent, by adding said basic agent, increasing the sludge pH to a value not more than a pH at which occurs degradation of said at least one organic constituent, flocculating the sludge and separating in the flocculated sludge dehydrated sludge from a liquid phase, said basic agent being a magnesian limestone compound of formula xCaCO3,(1−x)[yMg(OH)2+(1−Y) MgO], wherein 0,45:=x=0,75, and 0=y=, the treated sludge having, until after said separation, said value less than a pH at which occurs degradation of said at least one organic constituent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.