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US 9,359,239 B2Granted
Hybrid aerobic and anaerobic wastewater and sludge treatment systems and methods
AssigneeEvoqua Water Technologies LLC
InventorsWenjun Liu, Edward John Jordan, George W. Smith
Life of this patent
Estimating the term…
Abstract
A hybrid method and system of treating wastewater with reduced energy usage is disclosed. The treatment system has a sorption system, an anaerobic digester that digests or converts at least a portion of the solids or sludge from the sorption system, and an aerobic treatment tank that partially reduces oxygen demand of a portion of the sludge from the sorption tank.
Claims20
A wastewater treatment system comprising:
- a first treatment unit comprising one of a biological sorption tank, an aerobic treatment tank, an anoxic treatment tank, and an anaerobic digester, the first treatment unit having a treatment unit inlet and a mixed liquor outlet;
- a first separator having a first separator inlet in fluid communication with the mixed liquor outlet, a first solids-lean fluid outlet, and a first sludge outlet;
- an anaerobic digester having a digester inlet in fluid communication with the first sludge outlet, and a first digester outlet;
- a second separator having a second separator inlet in fluid communication with the first digester outlet, a second solids-lean fluid outlet, and a second sludge outlet, the second sludge outlet in fluid communication with the treatment unit inlet;
- a third separator fluidly connected downstream of the first sludge outlet and upstream of the digester inlet, and having a third solids-lean fluid outlet and a thickened sludge outlet, the first treatment unit, the first separator, and the third separator configured to produce a thickened sludge having a first concentration of a methanogenic bacteria, the anaerobic digester configured to produce a digested anaerobic sludge having a second concentration of the methanogenic bacteria, the first concentration being at least about 10% of the second concentration;
- and
- a precipitation vessel in fluid communication with the second solids-lean fluid outlet.
4 more elements
A wastewater treatment system comprising:
- a first treatment unit comprising one of a biological sorption tank, an aerobic treatment tank, an anoxic treatment tank, an anaerobic digester, and a sequencing batch reactor, the first treatment unit having a treatment unit inlet and a mixed liquor outlet;
- a first separator having a first separator inlet in fluid communication with the mixed liquor outlet, a first solids-lean fluid outlet, and a first sludge outlet;
- an anaerobic digester distinct from the first treatment unit and having a digester inlet in fluid communication with the first sludge outlet, and a first digester outlet;
- an aerobic stabilization tank having a stabilization tank inlet in fluid communication with the first digester outlet though a conduit fluidly connecting the stabilization tank inlet and the first digester outlet, and a stabilization tank outlet in fluid communication with the treatment unit inlet through a conduit fluidly connecting the stabilization tank outlet and the treatment unit inlet;
- the system configured to directing a first fraction of a solids-rich sludge from the first sludge outlet into the digester inlet in an amount resulting in a concentration of methanogenic bacteria present in the solids-rich sludge being at least 10% of a concentration of methanogenic bacteria present in mixed liquor in the anaerobic digester.
2 more elements
A wastewater treatment system comprising:
- a first treatment unit comprising one of a biological sorption tank, an aerobic treatment tank, an anoxic treatment tank, and an anaerobic digester, the first treatment unit having a treatment unit inlet and a mixed liquor outlet;
- a first separator having a first separator inlet in fluid communication with the mixed liquor outlet, a first solids-lean fluid outlet, and a first sludge outlet;
- an anaerobic digester having a digester inlet in fluid communication with the first sludge outlet, and a first digester outlet;
- a second separator having a second separator inlet in fluid communication with the first digester outlet, a second solids-lean fluid outlet, and a second sludge outlet, the second sludge outlet in fluid communication with the treatment unit inlet;
- a third separator fluidly connected downstream of the first sludge outlet and upstream of the digester inlet, the third separator containing a first consortium of bacteria with a concentration of methanogenic microorganisms that is a substantial fraction of a concentration of methanogenic microorganisms in a second consortium of bacteria contained in the anaerobic digester;
- and
- a precipitation vessel in fluid communication with the second solids-lean fluid outlet.
4 more elements
Dependencies are inferred from the claim text.