The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 23, 2014
Filed:
Mar. 16, 2010
Jean-pierre Hazard, Paris, FR;
Patrick Descamps, Marly le Roi, FR;
Jean-Pierre Hazard, Paris, FR;
Patrick Descamps, Marly le Roi, FR;
Degremont, , FR;
Abstract
The invention relates to a method for controlling oxygen supply in a tank () for biologically treating wastewater by alternating aeration including consecutive cycles, wherein each cycle comprises a first aeration phase and a second anoxic phase for reducing nitrites and nitrates formed during the preceding aeration phase, the tank is provided with sensors for measuring ammonia nitrogen () and for measuring nitrate () and optionally for measuring oxygen () that is dissolved in the tank liquor or in the liquor thereof exiting the tank, a method according to which the oxygen supply is controlled in the aeration phase when the reduction speed of the nitrate measurement is less than a bottom threshold and the cutoff of the oxygen supply is also controlled in the aeration phase when at least one of the following triggering events occurs: the reduction speed in the measurement of ammonia nitrogen becomes lower than a bottom threshold; the total sum of ammonia nitrogen and nitrate measurements becomes higher than a top threshold, said thresholds may be dependent on time delays and on a top threshold for the dissolved oxygen measurement.