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US 3,945,916 AGranted
Purification of effluent
AssigneeL Air Liquide, Societe Anonyme Pour L'Etude et L'Exploitation des Procedes Georges Claude
InventorPaul Boulenger
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Abstract
An improved process for the purification of effluent is disclosed in which oxygenated effluent is introduced into a treatment zone in which a part of the total amount of biologically activated sludge used in the process is fixed on immersed bacterial beds or discs which are mobile and a further part of said sludge is in suspension in effluent undergoing treatment.
Claims7
A process for the purification of a waste-containing liquid by oxygenation thereof with an oxygen-enriched gas in contact with a biologically activated sludge, comprising:
- a. introducing raw waste-containing liquid and biologically activated sludge into an inlet zone, thereby forming a waste/sludge mixture in said inlet zone;
- b. feeding the waste/sludge mixture, from the inlet zone, upwardly through a preliminary oxygenation zone and then downwardly through a descending passageway, connected to the top of the preliminary oxygenation zone, into a lower portion of a main treatment tank;
- c. oxygenating the waste/sludge mixture passing through the preliminary oxygenation zone by injecting oxygen-enriched gas upwardly into the preliminary oxygenation zone;
- d. recovering non-dissolved gas at the top of said preliminary oxygenation zone;
- e. discharging a predetermined portion of the recovered gas to atmosphere and recycling the remainder thereof to step (c);
- f. biologically treating the oxygenated waste in the treatment, entering from step (b);
- g. discharging to atmosphere any gases released by said treating step (f) in the treatment tank;
- and
- h. withdrawing a portion of the biologically activated sludge from the treatment tank and using said withdrawn sludge as at least a portion of the biologically activated sludge introduced in step (a).
6 more elements
Dependencies are inferred from the claim text.