Integrated hydroponic and fixed-film wastewater treatment systems and associated methods

Abstract

The wastewater treatment systems have a plurality of treatment zones including a first reactor for supporting biofilms for reducing a concentration of organics and solids from wastewater to be treated and for cyclically nitrifying and denitrifying the wastewater therein. A second reactor is for supporting biosolids, the supporting means including elements for digesting suspended solids in water exiting the first reactor. A portion of the water exiting the second reactor is recycled to the first reactor.

1 . A wastewater treatment system comprising: 
 a first reactor means comprising means for supporting biofilms for reducing a concentration of organics and solids from wastewater to be treated and for cyclically nitrifying and denitrifying the wastewater therein;    a second reactor means comprising means for supporting biosolids, the supporting means including means for digesting suspended solids in water exiting the first reactor means; and    means for recycling a portion of the water exiting the second reactor means to the first reactor means.    
     
     
         2 . The system recited in  claim 1 , further comprising means for mixing wastewater resident in at least one of the first and the second reactor means.  
     
     
         3 . The system recited in  claim 1 , wherein the first reactor means comprises manufactured media for supporting biofilm growth.  
     
     
         4 . The system recited in  claim 1 , further comprising means for controlling a residence time in the second reactor means to be sufficient for the substantially complete digestion of volatile suspended solids therein.  
     
     
         5 . The system recited in  claim 1 , wherein the second reactor means comprises plant roots adapted to retain biofilms thereon for enhancing nutrient removal and for digesting the biofilms.  
     
     
         6 . The system recited in  claim 1 , wherein the first reactor means comprises a vertical flow wetland.  
     
     
         7 . The system recited in  claim 6 , wherein the wetland is adapted to maintain a population of aquatic invertebrates therein.  
     
     
         8 . The system recited in  claim 1 , wherein the recycling means functions to recycle water at a rate between 1 and 10 times a rate of water entering the system.  
     
     
         9 . A method for treating wastewater comprising the steps of: 
 treating wastewater with a fixed-film treatment in an anoxic/aerobic environment;    treating water containing biofilms sloughed off in the anoxic/aerobic environment with an aerobic aquatic-root-zone treatment sufficient to substantially eliminate yield; and    recycling a portion of the filtered water to the anoxic/aerobic environment.    
     
     
         10 . A method for treating wastewater comprising the steps of: 
 supporting biofilms in a first environment for reducing a concentration of organics and solids from wastewater to be treated and for cyclically nitrifying and denitrifying the wastewater therein;    supporting biosolids in a second environment for digesting suspended solids in water exiting the first environment; and    recycling a portion of the water exiting the second environment to the first environment.    
     
     
         11 . The method recited in  claim 10 , further comprising the step of mixing wastewater resident in at least one of the first and the second environments.  
     
     
         12 . The method recited in  claim 10 , wherein the first environment comprises manufactured media for supporting biofilm growth.  
     
     
         13 . The method recited in  claim 10 , further comprising the step of controlling a residence time in the second reactor means to be sufficient for the substantially complete digestion of volatile suspended solids therein.  
     
     
         14 . The method recited in  claim 10 , wherein the second environment comprises plant roots adapted to retain biofilms thereon for enhancing nutrient removal and for digesting the biofilms.  
     
     
         15 . The method recited in  claim 10 , wherein the first environment comprises a vertical flow wetland.  
     
     
         16 . The method recited in  claim 15 , wherein the wetland is adapted to maintain a population of aquatic invertebrates therein.  
     
     
         17 . The method recited in  claim 10 , wherein the second environment comprises a hydroponic reactor.  
     
     
         18 . The method recited in  claim 10 , wherein the recycling step comprises recycling water at a rate between 1 and 10 times a rate of water entering the system.