Process for removing arsenic from water
CA 2121465 C · Owner: O'Connor, Rodney J. · Inventors: O'Connor, Mark A.; O'Connor, Rodney J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for treating arsenic-containing aqueous waste is described wherein the aqueous waste (10), treated if necessary to minimize the presence of material which reduce the efficiency of reverse osmosis membranes (74), is passed through an ultrafilter (50) to remove solids, followed by a chemical treatment (60) to adjust the pH to range from about 6 to 8 and to add anti-sealants and anti-fouling materials, then following to subject the chemically treated filtrate to a reverse osmosis process to result in a permeate stream (76) having less than about 50 parts per billion arsenic.
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 October 15, 1992 and granted February 26, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 15, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 15, 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.