Method of removing organic substances from effluents from pulp and paper manufacturing processes
US5013454A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 29, 1990 |
| Grant date | May 7, 1991 |
| Priority date | — |
| Expiry date | Oct 29, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/928
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A method of removing dissolved and colloidal macro-molecular organic substances from effluents from processes used in the manufacture of pulp and paper, wherein an acid sludge containing cellulose fibres and being acidified to a pH value of 1.6-2.5, is added to an effluent containing said organic substances, and the pH value is adjusted to 4.5-6.0 before the mixture is subjected to sedimentation to achieve precipitation of the fibres with said organic substances adhered thereto. According to the invention the fibres used as precipitant are subjected to mechanical treatment prior to said acidification, so that the fibres are broken and split open, increasing their specific fibre surface and thereby their ability to catch the organic substances in the effluent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.