Diffusion aeration for water and wastewater treatment

Abstract

A system for treating wastewater including at least one water-treatment pathway having at least one wastewater inlet, at least one oxygen-permeable, water-impermeable wall, separating an interior of the pathway from outside air, and at least one treated wastewater outlet and arranged for at least aerobic treatment of the wastewater as it flows from the at least one wastewater inlet to the at least one treated wastewater outlet, at least one wastewater supply conduit, supplying the wastewater to the at least one wastewater inlet of the water-treatment pathway and at least one treated wastewater conduit, supplying treated wastewater from the at least one treated wastewater outlet of the at least one water-treatment pathway.

1 - 34 . (canceled) 
     
     
         35 . A passive aeration system comprising:
 an elongated, membrane enclosed, generally horizontal flow passageway for water including:   an inlet for water to be treated at a first end of said generally horizontal flow passageway;   an outlet for treated water at a second end of said generally horizontal flow passageway; and   an oxygen permeable membrane, defining a tubular water pathway having an inside surface exposed to water and an outside surface exposed to ambient air, said oxygen permeable membrane supporting a biofilm on said inside surface, said oxygen permeable membrane being arranged to define at least one generally vertical airflow pathway communicating with said outside surface.   
     
     
         36 . A passive aeration system according to  claim 35  and wherein said generally horizontal flow passageway is spirally wound and said at least one generally vertical airflow pathway has a generally spiral cross section. 
     
     
         37 . A passive aeration system according to  claim 36  and wherein said generally horizontal flow passageway and said at least one generally vertical airflow pathway are enclosed within a generally vertical cylindrical enclosure. 
     
     
         38 . A passive aeration system according to  claim 37  and wherein said generally horizontal flow passageway has a tapered top surface region. 
     
     
         39 . A passive aeration system according to  claim 37  and wherein mutually adjacent inside surfaces of said tubular water pathway are separated by at least one interior spacer. 
     
     
         40 . A passive aeration system according to  claim 37  and wherein mutually adjacent outside surfaces of said tubular water pathway are separated by at least one exterior spacer. 
     
     
         41 . A passive aeration system according to  claim 37  and wherein mutually adjacent outside surfaces of said tubular water pathway are separated by a transverse distance of 4-20 mm. 
     
     
         42 . A passive aeration system according to  claim 36  and wherein said generally horizontal flow passageway has a tapered top surface region. 
     
     
         43 . A passive aeration system according to  claim 36  and wherein mutually adjacent inside surfaces of said tubular water pathway are separated by at least one interior spacer. 
     
     
         44 . A passive aeration system according to  claim 43  and wherein said spacer comprises at least one of: drainage netting; reinforcement mesh; fencing screen and three-dimensional plastic mesh grid. 
     
     
         45 . A passive aeration system according to  claim 36  and wherein mutually adjacent outside surfaces of said tubular water pathway are separated by at least one exterior spacer. 
     
     
         46 . A passive aeration system according to  claim 45  and wherein said spacer comprises at least one of: drainage netting; reinforcement mesh; fencing screen and three-dimensional plastic mesh grid. 
     
     
         47 . A passive aeration system according to  claim 36  and wherein mutually adjacent outside surfaces of said tubular water pathway are separated by a transverse distance of 4-20 mm. 
     
     
         48 . A passive aeration system according to  claim 35  and wherein said generally horizontal flow passageway and said at least one generally vertical airflow pathway are enclosed within a generally vertical cylindrical enclosure. 
     
     
         49 . A passive aeration system according to  claim 35  and wherein said generally horizontal flow passageway has a tapered top surface region. 
     
     
         50 . A passive aeration system according to  claim 35  and wherein mutually adjacent inside surfaces of said tubular water pathway are separated by at least one interior spacer. 
     
     
         51 . A passive aeration system according to  claim 50  and wherein said spacer comprises at least one of: drainage netting; reinforcement mesh; fencing screen and three-dimensional plastic mesh grid. 
     
     
         52 . A passive aeration system according to  claim 35  and wherein mutually adjacent outside surfaces of said tubular water pathway are separated by at least one exterior spacer. 
     
     
         53 . A passive aeration system according to  claim 52  and wherein said spacer comprises at least one of: drainage netting; reinforcement mesh; fencing screen and three-dimensional plastic mesh grid. 
     
     
         54 . A passive aeration system according to  claim 35  and wherein mutually adjacent outside surfaces of said tubular water pathway are separated by a transverse distance of 4-20 mm.