Method for arsenic removal from wastewater
CA 2089348 A1 · Owner: Andco Environmental Processes, Inc. · Inventors: Brewster, Michael D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure, A process and apparatus for removing arsenic from aqueous media is described. The process in general utilizes ferrous ion provided by an electrochemical cell which is added to the aqueous media in a first step, followed by mild oxidizing conditions generated by the addition of hydrogen peroxide. The ferrous ion then forms an hydroxide which is oxidized to an oxyferric oxide and the arsenic present at a +3 oxidation state is oxidized to a +5 state whereupon the oxyacid complexes with the oxyferric oxide. A precipitate then is formed which consists of ferric arsenate, and the hydroxy ferric oxide - oxyacid complex. Heavy metals may also be removed by the process.
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 February 11, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 11, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 11, 2015.
- 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.