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US 10,703,657 B2Granted
Waste water treatment method using membrane separation-activated sludge
AssigneeToray Industries, Inc.
InventorsSeiko Kantani, Yohito Ito, Hideaki Ando
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AssigneeToray Industries, Inc.
InventorsSeiko Kantani, Yohito Ito, Hideaki Ando
Estimating the term…
In a waste water treatment method using membrane separation-activated sludge, when, during filtration while supplying air using an immersion-type membrane separation unit loaded with multiple flexible membranes, the filtration differential pressure of the membranes at a set filtration flow rate exceeds a specified value P2 with respect to the filtration differential pressure P1 of the initial period of operation, membrane filtration is continued with air supply stopped until the filtration differential pressure P3 becomes P3≥P1+20 [kPa]. Then with the filtration flux or filtration pressure being smaller or negative compared to when filtering while supplying air, air is supplied and after the filtration differential pressure P4 during filtration reaches P4≤P1+5 [kPa], filtration is returned to filtration while supplying air.
A wastewater treatment method by a membrane bioreactor, comprising, during operation for performing filtration while performing air supply using a submerged type membrane separation unit in which a plurality of membrane elements having flexibility are loaded, when a filtration pressure difference of the membrane elements exceeds a predetermined value P2, to a filtration pressure difference P1 at an initial stage of the operation, performing filtration until a filtration pressure difference P3 satisfies P3≥P1+20 [kPa] in a state that an air supply amount is smaller than that during the operation for performing the filtration while performing the air supply, then performing the air supply in a state that a filtration flux or a filtration pressure is smaller than that during the operation for performing the filtration while performing the air supply or negative, and being returned to the operation for performing the filtration while performing the air supply after a filtration pressure difference P4 during performing the filtration reaches P4≤P1+5 [kPa].
Dependencies are inferred from the claim text.