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Expired Canadian patentCanada

Wastewater treatment system

CA 2453228 C · Owner: Hunt, Patrick G. · Inventors: Hunt, Patrick G.; Szogi, Ariel A.; Vanotti, Matias B.

CIPO record

Overview

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Wastewater treatment systems and processes for removal of solids pathogens, nitrogen, and phosphorus from municipal and agricultural wastewater include nitrification of wastewater and increasing the pH of the nitrified wastewater by adding a metallic-containing salt and hydroxide to precipitate phosphorus to form a useable effluent having a specified nitrogen:phosphorus ratio that is useful as a fertilizer or spray for remediation of contaminated soils. The presence of infectious microorganism such as enteropathogenic bacteria and picarnoviruses will be reduced in the useable effluent. The precipitated phosphorus is recovered and used to form useable phosphorus products.

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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Filed July 12, 2002 and granted December 31, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 12, 2022.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 12, 2024.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJuly 12, 2002
GrantedDecember 31, 2013
Term endedJuly 12, 2022
Patent numberCA 2453228 C
Classification (IPC)C02F3/00 +2 more

Timeline

Timeline From CIPO dates

2003200520072009201120132015201720192021Application filedJuly 12, 2002Patent grantedDec 31, 2013Term endedJuly 12, 2022

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.