Biological wastewater purification with a downstream precipitation stage
CA 2018139 C · Owner: Morper, Manfred · Inventors: Reiser, Wolfgang; Morper, Manfred
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Wastewater containing impurities refractory to secondary treatment is first intraduced into an aerobic biological treatment stage operating with an oxygen-enriched stream and subsequently into a precipitation stage where the biologically treated wastewater is combined with Ca(OH)2 to precipitate Ca(OH)2/CaCO3 sludge which adsorbs or occludes impurities. The clear liquid separated from the resultant sludge, is passed to a second precipitation stage where it reacts with a CO2 and oxygen-containing waste gas at least: in part from the aerobic biological treatment stage, thereby forming additional CaCO3. Waste gas withdrawn from the second precipitation stage, being enriched in oxygen is …
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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 May 29, 1990 and granted February 13, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 29, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 29, 2012.
- 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
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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.