Method for treating water within a sequencing batch reactor, including an in-ine measurement of the nitrite concentration

Abstract

The invention relates to a method for treating water laden with nitrogen in the form of ammonium within a sequencing batch reactor, said method including at least: a first step (i) of feeding said water into said sequencing batch reactor (10); an aerated nitrosation step (ii); an anoxic denitrosation step (iii); and a step (iv) of extracting treated water from said reactor. According to the invention, such a method further includes an in-line measurement of the nitrite concentration of said water in said reactor, a step of measuring the pH of said water contained in said reactor, a step of determining information that is representative of the nitrous-acid (HNO2) concentration of said water contained in said reactor on the basis of said in-line measurement of the nitrite concentration and said pH measurement, and a step of controlling the duration of said aerated nitrosation step (ii) in accordance with said nitrous-acid concentration.

Description

technical field 1. Field of invention [0001] The field of the invention is that of the treatment of water loaded with nitrogen in the form of ammonium. The present invention is especially applicable to the treatment of industrial or urban sewage (effluents) such as the supernatant of anaerobic digestion tanks, the sewage produced by sludge treatment by wet oxidation, the condensate of gas treatment, the condensate of purification sludge treatment, sewage discharge Leachate, slaughterhouse effluent, pig manure liquid or any other type of effluent loaded with nitrogen in the form of ammonium. [0002] More particularly, the present invention relates to a water treatment process using a sequential bioreactor (SBR) in which, inter alia, aerated and anoxic biological treatment steps are carried out successively. Background technique [0003] 2. Existing technology [0004] Biological water treatment methods are generally used to reduce the level of nitrogenous pollutants in w...

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Problems solved by technology

[0034] More recently, studies by Foley et al. indicated that nitrous oxide production is often associated with large concentrations of nitrite in bioreactors, but the mechanisms responsible for nitrite and nitrous oxide formation are numerous and very Complex (Jeffrey Foley, David de Haas, Zhiguo Yuan, Paul Lant, 2010,"Nitrous oxide generation in full-scale biological nutrient removal wastewater treatment plants", Water research.44:831-844)

[0035] These scientific publications, some of which teach contradictory ones, agree that the method of water treatment by nitritation-denitritation has the disadvantage of producing nitrous oxide, the mechanism of which is complex and not yet understood

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