Secondary treatment of an integrated paper mill effluent
CA 2068101 A1 · Owner: Vipat, Vasudha S. · Inventors: Vipat, Vasudha S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In treating effluent from an integrated paper mill having bleach plant effluent (including kraft mill effluent) and paper mill effluent (including effluent from a mechanical pulp mill) it has been found that if the two effluents are separately biologically treated and the recycled activated sludge directed to treatment of the bleach plant kraft mill effluent contains a significant portion of activated sludge derived from the treatment of the paper mill effluent that a significantly higher percentage of the absorbable organic halogens (AOX) can be removed from the bleach plant effluent.
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 May 6, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 6, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 6, 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.