System and process for purifying waste water which contains nitrogenous compounds
CA 2135897 C · Owner: Paques B.V. · Inventors: Mulder, Ronald; Vellinga, Sjoerd Hubertus Jozef
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a system and a process for purifying nitrogenous waste water by biological nitrification and denitrification. The system comprises at least two essentially separated reactor chambers a liquid sup-, ply (4) and a liquid discharge (5). The first aerated reactor chamber (1) is, provided at the top with an overflow to the second oxygen-depleted reactor, chamber (2). The oxygen-depleted reactor chamber (2) is divided at the top into a degassing chamber (7) and a settling chamber (8) having an overflow (9) to the liquid discharge. The first reactor chamber is provided with an air supply (11, 18) and an air discharge (12) located above the supply. The first reactor chamber …
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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 June 10, 1993 and granted September 9, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 10, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 10, 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
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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.