Photodegradation of toxic contaminants
US5698829A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 1995 |
| Grant date | Dec 16, 1997 |
| Priority date | — |
| Expiry date | Sep 21, 2015 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA62D2101/28
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A process is provided herein for extracting organic toxic contaminants including pentachlorophenol, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans, from wood, e.g., utility poles, fence posts, or railway ties. The process comprises extracting the wood with a supercritical fluid in conjunction with an entrainer having wood swelling properties and an agent to break the hydrogen bond between the organic toxic contaminants and the wood, at conventional supercritical fluid extraction temperatures and pressures. The process is further improved by exposing, either in a slurry of the wood phase, or in a liquid phase resulting from such extraction, the contaminants to UV, e.g., sunlight, in the presence of a photosensitizer. The present invention also provides for the photodegradation of a solution of organic toxic chemicals including pentachlorophenol, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans, by exposing such solution to UV, e.g., sunlight, in the presence of a photosensitizer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.