Process for the decolorization of pulp mill process streams
US4695386A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 20, 1985 |
| Grant date | Sep 22, 1987 |
| Priority date | — |
| Expiry date | May 20, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/928
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A process for the decolorization of pulp mill process streams is described. The effluent from the process contains color bodies and organic materials, and is first fed to an acidification reactor where the pH is reduced. This causes a portion of the color bodies to precipitate. A flocculant is added to coagulate the precipitated lignins, and the solution is filtered. The filtrate then passes through a series of chambers where it is contacted with activated carbon in an advanced separation device (ASD). The regeneration of the carbon occurs simultaneously in other chambers of the ASD. The treated filtrate with significantly lower color bodies passes out of the ASD in a substantially continuous stream.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.