Methods and Apparatus For Biological Treatment of Waste Waters

Abstract

In a vertical shaft bioreactor, improved devices and methods are provided for enhanced secondary and/or tertiary treatment of wastewater, including residential, municipal and industrial wastewater. The devices and methods of the invention are useful for enhanced secondary wastewater treatment, including BOD and TSS removal. Tertiary treatment can alternately or additionally be achieved in the bioreactor with nitrification of ammonia, with nitrification and denitrification, and with nitrification, denitrification, and chemical phosphorus removal. A vertical shaft bioreactor is also provided which achieves thermophilic aerobic digestion and pasteurization of sewage sludges, optionally to produce class A biosolids.

1 .- 66 . (canceled) 
   
   
       67 . An improved waste water treatment process utilizing a long vertical shaft bio-reactor comprising simultaneously diverting a predetermined fraction of oxygen-containing gas rising in a primary upflow channel of said bio-reactor into one or more superior upflow channels, and simultaneously diverting a different fraction of total fluid flow into one or more of said superior upflow channels, wherein non-plugging flow in said primary upflow channel is achieved without the use of orifice plates. 
   
   
       68 . The improved waste water treatment process of  claim 67 , wherein flow velocities in said primary upflow channel can be effectively adjusted to as low as 0.25 ft./sec. 
   
   
       69 . The improved waste water treatment process of  claim 67 , further comprising recycling of degassed liquid and/or raw influent in a first treatment zone of the bio-reactor to allow deoxygenation without mechanical mixing. 
   
   
       70 . The improved waste water treatment process of  claim 67 , further comprising recycling of degassed liquid and/or raw influent in a first treatment zone of the bio-reactor to allow denitrification without mechanical mixing. 
   
   
       71 . The improved waste water treatment process of  claim 67 , further comprising maintaining an aeration rate between about 0.2-0.5 mg/L DO without changing residence time in said primary upflow channel of the bio-reactor. 
   
   
       72 . An improved method for constructing a vertical shaft bioreactor comprising the steps of:
 placing a cylindrical reactor housing defining an inner reactor wall into an excavated reactor site,   inserting a modular reactor component having a central conduit surrounded by one or more channel-forming radial partition(s) within said cylindrical housing, said modular reactor component being deformed during insertion to displace said radial partition(s) away from said inner wall by expanding a diameter of said central conduit in a direction generally perpendicular to said radial partition(s);   relaxing deformation of said modular reactor component to bring said radial partition(s) in proximity to said inner wall.   
   
   
       73 . The method for constructing a vertical shaft bioreactor according to  claim 72 , wherein said central conduit is expanded mechanically by a spreader sized and dimensioned for insertion within the central conduit. 
   
   
       74 . The method for constructing a vertical shaft bioreactor according to  claim 73 , wherein the spreader has paired, opposed and reciprocating spreader parts which can be manually, reciprocatingly repositioned between relaxed and expanded configurations.