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US5698829A Expired / Lapsed US ⏱️ 0.0 years remaining

Photodegradation of toxic contaminants

Assignee: Bell Canada Inc
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Filing: 1995-09-21
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Granted: 1997-12-16
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Expires: 2015-09-21
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Abstract

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.

Inventors

  • 👤 John N. R. Ruddick
  • 👤 Futong Cui

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 15:58
CPC Classifications
A; A62; A62D; A62D3/00; A62D3/10; A62D3/17; A62D3/176; A62D2101/00; A62D2101/20; A62D2101/22; A62D2101/28

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 55 words
A process for photodegrading organic toxic chemicals including pentachlorophenol, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans which process comprises: providing a solution of said organic toxic chemicals, a solvent and a photosensitizing amount of a photosensitizer selected from the group consisting of a porphyrin and a phthalocyanine; and exposing said solution to radiation including UV or sunlight.
Claim 2
Dependent Claim 55 words
A process for photodegrading organic toxic chemicals including pentachlorophenol, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans which process comprises: providing a solution of said organic toxic chemicals, a solvent and a photosensitizing amount of a photosensitizer selected from the group consisting of a porphyrin and a phthalocyanine; and exposing said solution to radiation including UV or sunlight.
Claim 3
Dependent Claim 11 words
The process of claim 1 wherein said photosensitizer is a porphyrin.
Claim 4
Dependent Claim 10 words
The process of claim 2 wherein porphyrin is protoporphyrin IX.
Claim 5
Dependent Claim 11 words
The process of claim 1 wherein said photosensitizer is a phthalocyanine.
Claim 6
Dependent Claim 10 words
The process of claim 4, wherein said photosensitizer is phthalocyaninetetrasulfonate.
Claim 7
Dependent Claim 12 words
The process of claim 1 wherein said solvent is a water-miscible solvent.
Claim 8
Dependent Claim 14 words
The process of claim 6 wherein said water-miscible solvent is acetonitrile, methanol or ethanol.
Claim 9
Dependent Claim 46 words
A process for photodegrading organic toxic chemicals including pentachlorophenol, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans, which process comprises: providing a solution of said organic toxic chemicals, a solvent, a photosensitizing amount of a photosensitizer and an amine; and exposing said solution to radiation including UV or sunlight.
Claim 10
Dependent Claim 46 words
A process for photodegrading organic toxic chemicals including pentachlorophenol, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans, which process comprises: providing a solution of said organic toxic chemicals, a solvent, a photosensitizing amount of a photosensitizer and an amine; and exposing said solution to radiation including UV or sunlight.
Claim 11
Dependent Claim 10 words
The process of claim 8, wherein said amine is triethanolamine.
Claim 12
Dependent Claim 12 words
The process of claim 8, wherein said solvent is a water-miscible solvent.
Claim 13
Dependent Claim 14 words
The process of claim 10, wherein said water-miscible solvent is acetonitrile, methanol or ethanol.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-12-15 2001-06-16 2001-12-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-12-15 2005-06-16 2005-12-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-12-15 2009-06-16 2009-12-16 $7700.00 Window Closed / Lapsed

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