Purifying aqueous effluent from a pulp mill using electro chemical membrane device
US5792315A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 1996 |
| Grant date | Aug 11, 1998 |
| Priority date | — |
| Expiry date | Feb 20, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S162/08
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
This invention is related to a process for producing pulp from a cellulosic starting material, wherein an aqueous process effluent is purified from metal impurity cations. This process comprises that the effluent is purified by an electro-chemical membrane treatment in an electrochemical membrane device comprising a unit cell through which an electric current is passed between an anode side and a cathode side of said cell, said cell comprising at least two ion permeable membranes forming between them at least one compartment, said effluent being fed into an effluent feed compartment in said cell, in which the effluent is purified by removing with the electric current metal impurity cations from the effluent through a cation selective membrane on the cathode side of said compartment, and withdrawing from said compartment the purified effluent. The purified effluent may be recirculated to the pulp mill process, e.g. as washing water.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.