Methods and systems for treating wastewater
AssigneeEvoqua Water Technologies LLC
InventorsWenjun Liu, Edward John Jordan, Paul M. Gallagher
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Abstract
A method and system of treating wastewater is disclosed. The treatment system has a nitrification-denitrification system comprising a sorption system, a biofilm system, and an anaerobic digester that digests or converts at least a portion of the solids or sludge from the sorption system and biofilm system.
Claims27
A method for treating wastewater comprising:
- providing a wastewater to be treated;
- denitrifying the wastewater in a first biological reactor to produce a denitrified mixed liquor;
- nitrifying the denitrified mixed liquor with a nitrifying biofilm on a carrier and biosorbing undesirable constituents from the denitrified mixed liquor with a suspended biomass in a second biological reactor;
- separating a first portion of the nitrified mixed liquor in a separator to produce a solids-rich sludge and a treated effluent having a total nitrogen concentration of less than about 10 milligrams of elemental nitrogen per liter;
- and
- combining a second portion of the nitrified mixed liquor with the wastewater to be treated.
A wastewater treatment system comprising:
- a source of a wastewater to be treated;
- a first biological reactor having an inlet fluidly connected downstream from the source of the wastewater;
- a biological sorption tank comprising a biofilm carrier, and having an inlet fluidly connected to the first biological reactor, the biological sorption tank constructed and arranged to maintain an effluent having a total nitrogen concentration of less than about 10 milligrams elemental nitrogen per liter and a hydraulic retention time of less than about three hours;
- a separator having a sludge outlet, an effluent outlet, and an inlet fluidly connected downstream of the biological sorption tank;
- and
- a sludge recycle line fluidly connecting an outlet of the separator to the source of wastewater.
A method of facilitating wastewater treatment in a wastewater treatment system for reducing a concentration of a nitrogen containing compound from a wastewater, the system having a source of wastewater, an anoxic reactor, an aerobic reactor, a mixed liquor recycle stream fluidly connecting an outlet of the aerobic reactor to the anoxic reactor, a separator, and a sludge recycle stream fluidly connecting an outlet of the separator to the anoxic reactor, the method comprising:
- introducing a biofilm carrier into the aerobic reactor;
- and
- fluidly connecting a solids-rich outlet of the separator to an anaerobic digester.
A method for treating wastewater comprising:
- providing a wastewater to be treated;
- promoting denitrification of the wastewater in a first biological reactor to produce a first biologically treated mixed liquor;
- promoting biological sorption of the first biologically treated mixed liquor and biofilm growth in a second biological reactor;
- separating an effluent of the second biological reactor to produce a solids-rich sludge and a treated effluent having a total nitrogen concentration of less than about 10 milligrams of elemental nitrogen per liter;
- and
- treating the solids-rich sludge in a third biological reactor to produce a biologically treated sludge.
Dependencies are inferred from the claim text.