Method and apparatus for treating wastewater

Abstract

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 wastewater treatment system comprising: 
 a first treatment zone fluidly connected to a second treatment zone;    a fluidizable media carrying bacteria positioned in the first treatment zone; and    a membrane module comprising a filter membrane positioned in the second treatment zone.    
   
   
       2 . The wastewater treatment system of  claim 1 , further comprising: 
 an oxygen depleting zone fluidly connected to the first treatment zone and the second treatment zone.    
   
   
       3 . The wastewater treatment system of  claim 2 , further comprising an equalization tank positioned upstream of the first treatment zone.  
   
   
       4 . The wastewater treatment system of  claim 3 , further comprising a pretreatment unit positioned upstream of the equalization tank.  
   
   
       5 . The wastewater treatment system of  claim 4 , wherein the pretreatment unit is a trap.  
   
   
       6 . The wastewater treatment system of  claim 1 , wherein the membrane module is disposed at any angle in the second treatment zone.  
   
   
       7 . The wastewater treatment system of  claim 6 , wherein the module is disposed horizontally in the second treatment zone.  
   
   
       8 . The wastewater treatment system of  claim 1 , wherein the first treatment zone is an anoxic zone.  
   
   
       9 . The wastewater treatment system of  claim 8 , wherein the second treatment zone is an aerobic zone.  
   
   
       10 . The wastewater treatment system of  claim 1 , further comprising means for fluidizing the fluidizable media.  
   
   
       11 . The wastewater treatment system of  claim 10 , wherein the means for fluidizing the fluidizable media comprises a manifold positioned in the first compartment below the fluidizable media.  
   
   
       12 . The wastewater treatment system of  claim 10 , further comprising means for maintaining the fluidizable media within the first treatment zone.  
   
   
       13 . A method of treating wastewater comprising: 
 contacting a wastewater with anoxic bacteria immobilized on a fluidized media to produce a first water product;    contacting the first water product with air to form a second water product; and    passing the second water product through a filter membrane to produce a concentrated mixed liquor and a filtrate.    
   
   
       14 . The method of treating wastewater of  claim 13 , further comprising removing at least a portion of dissolved oxygen from the concentrated mixed liquor.  
   
   
       15 . The method of treating wastewater of  claim 14 , further comprising contacting a portion of the first water product with the concentrated mixed liquor to form a secondary wastewater.  
   
   
       16 . The method of treating wastewater of  claim 15 , further comprising contacting a portion of the secondary wastewater with the anoxic bacteria fixed on the fluidized media.  
   
   
       17 . 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 concentrated mixed liquor and a filtrate; and    discharging the filtrate.    
   
   
       18 . The method of treating wastewater of  claim 17 , further comprising removing at least a portion of dissolved oxygen from the concentrated mixed liquor.  
   
   
       19 . The method of treating wastewater of  claim 18 , further comprising combining a second portion of the first treated wastewater with the concentrated mixed liquor to form a secondary wastewater.  
   
   
       20 . The method of treating wastewater of  claim 19 , further comprising passing a portion of the secondary wastewater through the fluidized media.  
   
   
       21 . The method of treating wastewater of  claim 19 , wherein passing the first portion of the first treated wastewater through the membrane module occurs under hydrostatic pressure.