Degremont

Pavel Chudoba

Roger Pujol

Michele Pannier

Claude Grimaud

The invention is a biological process for purifying waste water in order to produce an effluent with a low content of carbon and of oxygenated nitrogen compounds. The process includes an initial step of mixing the waste water in a biological reactor with activated sludge to denitrify the resulting mixture. Then, air is introduced into the mixture to form an anoxic sludge thereby directly oxidizing carbon present in the anoxic sludge and removing carbon therefrom, simultaneous with the denitrification. The anoxic sludge is clarified to separate it from a denitrified intermediate effluent. The clarified anoxic sludge is recycled to the biological reactor. Then, intermediate effluent is nitrified to form a nitrified liquor and a portion of the nitrified liquor is recycled into the anoxic sludge that is present in the biological reactor, thereby subjecting the anoxic sludge to oxygen present in nitrified compounds and consequently further removing carbon from the anoxic sludge, simultaneous with the denitrification. The rate of removal of carbon is controlled as a function of the flow rate/pollution characteristics of the anoxic sludge while a redox potential of the anoxic sludge is continuously measured. A nitrate concentration of the intermediate effluent is continuously measured. There is an adjustment of an amount of air introduced into the anoxic sludge in accordance with the measured redox potential and measured nitrate concentration. A recycling flow rate of the nitrified liquor is adjusted in accordance with the measured redox potential and measured nitrate concentration. The remaining nitrified liquor is the final effluent.

Method for purifying carbon-containing pollution and denitrifying waste water in oxygenic medium

Method for eliminating phosphorous contained in effluents

Process for the treatment of liquid effluents, such as waste water, for the purpose of removal of carbon, nitrogen and phosphorus pollution using an activated sludge, according to which the effluent, after having been subjected to mechanical pretreatments, is brought into contact with the activated sludge. The effluent/activated sludge mixture is the subjected to clarification/settling in order to separate the treated water from the thickened sludge, the latter then being recycled at the head of the aeration treatment and the excess sludge being continuously discharged. An inert material of inorganic origin is injected into the activated sludge, this material being immediately and homogeneously dispersed in the activated sludge, in order to create a mixed culture containing both, and in a single bacterial floc, free heterotrophic species and autotrophic species partially fixed on the particles of the said material within the floc. The structure of the latter contains in the order of 40 to 65% of organic matter, the remainder being the said inert material, consisting of one or a number of particles of the said material surrounded by activated sludge. The extraction of the excess sludge is carried out continuously and without separation of the injected material.

Process for the treatment of liquid effluents by activated sludge

Process for the biological treatment of water using a biological reactor containing a culture of microorganisms, immobilized on a granular support material, according to which an expendable powdery material is injected into the said reactor, said process being performed so as to ensure a self-selection and a self-regulation of the support material of the particle size necessary for the biological process.

Growing community of inventors

Le Peco, France

Pavel Chudoba