System for cleaning contaminated water
CA 2108982 C · Owner: Gillham, Robert Winston · Inventors: Gillham, Robert Winston
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Water contaminated with halogenated organics including chloroform, trichloroethane, solvents pesticides, etc. is treated, by passing the water through a permeable mixture of activated carbon and iron fillings. When the mixture is brought to a negative Eh voltae, the metal causes the contaminants to undergo chemical breakdown. The activated carbon acts to retard the contaminant, giving it a long residence time close to the iron. The negative Eh conditions demand oxygen exclusion, such that a favoured application is to place the mixture in a trench below the water table in an aquifer, in the path of a plume of contaminant. The mixture may also be contained in a tank above or in, the …
Read the whole patent
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 April 24, 1992 and granted July 2, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 24, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 24, 2014.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.