Method for thickening or dehydrating sludge
US9790111B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 28, 2013 |
| Grant date | Oct 17, 2017 |
| Priority date | — |
| Expiry date | Mar 24, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2103/32
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Disclosed is a method for thickening or dehydrating sludge, which includes at least: a) a step of adding flocculants to the sludge to be treated; b) a step of flocculation by agitation of the sludge with the flocculants thus added in order to form a mixture of flocks and an aqueous solution; c) a step of mechanical separation of the flocks and the aqueous solution formed during the preceding step; d) a step of recovering the aqueous solution and the flocks that make up a treated sludge; wherein: the added flocculants are made up of at least one cationic starch (S) and at least one cationic polyacrylamide (P); the cationic starch or starches (S) including a fixed weight percentage of nitrogen of at least 2%; and the weight ratio (R) ws/(ws+wp), expressed as solids, is included between 0.6 and 0.99.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.