Filtration method and apparatus
AssigneeSiemens Water Technologies Corp.
InventorEdward John Jordan
Life of this patent
Estimating the term…
Abstract
The invention relates to a membrane bioreactor process combined with an advanced biological sludge digestion process that provides significant improvements in sludge digestion by reducing the costs and resources required for disposing of digested sludge. The offline treatment vessel is used to solubilize the organic material by operating in a very low oxygen environment. Digested process fluid is transferred back to the membrane bioreactor. The processes and apparatus substantially reduce the production of waste sludge.
Claims19
A method for treating an influent stream comprising a digestible waste, the method comprising:
- filtering a mixed liquor in the membrane bioreactor, wherein the mixed liquor is contacted with outer surfaces of a plurality of porous hollow fiber membranes, and wherein a permeate is removed from lumens of the membranes;
- removing biological solids from the membrane bioreactor by recycling a substrate containing biological solids to an offline treatment vessel via a recycle loop, whereby a preselected concentration of biological solids is maintained within the membrane bioreactor;
- digesting biological solids in the offline treatment vessel;
- and
- conducting an effluent stream from the offline treatment vessel to the membrane bioreactor, wherein the effluent stream comprises at least a portion of the mixed liquor,
- wherein the step of removing biological solids further comprises the step of passing the substrate containing biological solids through a hydrocyclone, whereby inert solids are removed, wherein the hydrocyclone is part of the recycle loop.
A method for treating an influent stream comprising a digestible waste, the method comprising:
- filtering a mixed liquor in the membrane bioreactor, wherein the mixed liquor is contacted with outer surfaces of a plurality of porous hollow fiber membranes, and wherein a permeate is removed from lumens of the membranes;
- removing biological solids from the membrane bioreactor by recycling a substrate containing biological solids to an offline treatment vessel via a recycle loop, whereby a preselected concentration of biological solids is maintained within the membrane bioreactor;
- digesting biological solids in the offline treatment vessel;
- and
- conducting an effluent stream from the offline treatment vessel to the membrane bioreactor, wherein the effluent stream comprises at least a portion of the mixed liquor,
- wherein the step of removing biological solids further comprises the step of passing the substrate containing biological solids through a screen, whereby inert solids are removed, wherein the screen is part of the recycle loop.
An apparatus for filtering a liquid containing solids, the apparatus comprising:
- a membrane bioreactor comprising at least one membrane module, the membrane module comprising a plurality of porous membranes, wherein the membrane module is configured such that, in operation, a substrate comprising an activated sludge is contacted with outer surfaces of the membranes, and a treated water is removed from lumens of the membranes;
- a biological sludge treatment vessel configured to operate in an anaerobic environment wherein a process fluid is digested, wherein at least a portion of the digested process fluid is transferred to the membrane bioreactor, and wherein at least a portion of the substrate in the membrane bioreactor is transferred to the biological sludge treatment vessel;
- and
- a surge tank configured to receive an outflow from the membrane bioreactor.
An apparatus for filtering a liquid containing solids, the apparatus comprising:
- a membrane bioreactor comprising at least one membrane module, the membrane module comprising a plurality of porous membranes, wherein the membrane module is configured such that, in operation, a substrate comprising an activated sludge is contacted with outer surfaces of the membranes, and a treated water is removed from lumens of the membranes;
- a biological sludge treatment vessel configured to operate in an anaerobic environment wherein a process fluid is digested, wherein at least a portion of the digested process fluid is transferred to the membrane bioreactor, and wherein at least a portion of the substrate in the membrane bioreactor is transferred to the biological sludge treatment vessel;
- and
- an auxiliary screen, wherein the auxiliary screen comprises openings having an average size in a longest dimension of from about 6 mm to about 25 mm.
Dependencies are inferred from the claim text.