Method and plant for biological treatment of aqueous effluents for purification thereof
AssigneeDegremont
InventorSerge Morgoun
Life of this patent
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Abstract
The invention relates to a method for the biological treatment of effluents contaminated with impurities of urban or industrial origin, characterised in employing a single aeration tank (1) with a high mass charge in which the raw effluent or mechanically pre-treated effluent is mixed without previous decantation with a free microbial culture of the activated sludge type, growing in a lightly aerated medium, of the order of 0.1 to 0.2 kg O2/kg BOD5 removed, the organic charge applied having a value equal to or greater than at least 2 kg COD/kgSM/day, preferably equal to or greater than 4 kg COD/kgSM/day, the hydraulic residence time for the raw effluent in the single aeration tank being between 30 and 90 minutes, preferably between 40 and 60 minutes.
Claims10
A method for the biological treatment of effluents contaminated with impurities of municipal or industrial origin, characterized in that it employs a single aeration tank (1) with high mass loading in which the raw or mechanically pretreated effluent is mixed, without prior settling, with a free microbial culture of the activated sludge type, growing in a lightly aerated medium, of the order of 0.1 to 0.2 Kg O2/kg BOD5 removed, the applied organic loading being equal to or greater than at least 2 Kg COD/kg SM/day, preferably equal to or greater than 4 Kg COD/Kg SM/day, the hydraulic residence time of the raw effluent in the single aeration tank being between 30 and 90 minutes, and preferably between 40 and 60 minutes, and in that, in said single aeration tank (1) a portion of the dissolved carbon pollution and nearly the entire colloidal and particulate fraction of the effluent are biosorbed by the activated sludge floc.
Dependencies are inferred from the claim text.