Method for treating wastewater
View Patent ↗This invention is directed to a wastewater treatment system having a fluidizable media carrying anoxic bacteria in a first treatment zone and a filter membrane positioned in a second treatment zone. A wastewater is contacted with the fluidizable media and further contacted with air and a filter membrane.
1. A method of treating wastewater comprising:
contacting a wastewater with anoxic bacteria immobilized on a fluidized media to produce a first water product;
contacting at least a first portion of the first water product with air to form a second water product;
passing the second water product through a filter membrane to produce a filtrate and a concentrated mixed liquor comprising dissolved oxygen;
removing at least a portion of the dissolved oxygen from the concentrated mixed liquor to form a reduced oxygen content concentrated mixed liquor;
contacting at least a second portion of the first water product with the reduced oxygen content concentrated mixed liquor to form a secondary wastewater; and
contacting the secondary wastewater with the anoxic bacteria immobilized on the fluidized media.
2. The method of treating wastewater of claim 1 , further comprising contacting a portion of the secondary wastewater with the anoxic bacteria fixed on the fluidized media.
3. A method of treating wastewater comprising:
passing a wastewater through a fluidized media carrying anoxic bacteria to produce a first treated wastewater;
passing a first portion of the first treated wastewater through a membrane module comprising a filter membrane to produce a filtrate and a concentrated mixed liquor comprising dissolved oxygen;
discharging the filtrate;
removing at least a portion of the dissolved oxygen from the concentrated mixed liquor to form a reduced oxygen content concentrated mixed liquor;
combining a second portion of the first treated wastewater with the reduced oxygen content concentrated mixed liquor to form a secondary wastewater; and
contacting the secondary wastewater with the fluidized media carrying anoxic bacteria.
4. The method of treating wastewater of claim 3 , further comprising passing a portion of the secondary wastewater through the fluidized media.
5. The method of treating wastewater of claim 3 , wherein passing the first portion of the first treated wastewater through the membrane module occurs under hydrostatic pressure.
6. The method of claim 1 , wherein contacting the wastewater with anoxic bacteria comprises contacting the wastewater with denitrifying bacteria.
7. The method of claim 1 , wherein contacting the wastewater with anoxic bacteria immobilized on the fluidized media comprises contacting the wastewater with the anoxic bacteria immobilized on a fluidized media having a specific gravity substantially equal to a specific gravity of the wastewater.
8. The method of claim 3 , wherein passing the wastewater through a fluidized media carrying anoxic bacteria comprises passing the wastewater through a fluidized media carrying denitrifying bacteria.
9. The method of claim 3 , wherein passing the wastewater through the fluidized media comprises passing the wastewater through a fluidized media having a specific gravity substantially equal to a specific gravity of the wastewater.