Bioreactor carrier, process for producing the carrier and method for using the same

Abstract

There are disclosed a bioreactor carrier comprising a (A) water swellable thermoplastic resin, preferably water swellable thermoplastic polyurethane resin and a (B) specific inorganic filler which is added thereto at the time of producing and/or molding said resin, characterized in that the specific gravity of the carrier on swelling in water is controlled within the range of 1.02 to 1.35; a process for producing the bioreactor carrier; and a process for denitrifying treatment of organic waste water which comprises nitrifying and denitrifying nitrogen components in the organic waste water with microbes by the use of the above bioreactor carrier. The bioreactor carrier has high physical strength, can be readily produced and uniformly fluidized in a reactor, and enables microbial and enzymatic reactions to be effectively performed.

What is claimed is:  
     
         1 . A process for producing a bioreactor carrier, the specific gravity of which on swelling in water is controlled within the range of 1.02 to 1.35, comprising: 
 blending at least one inorganic filler selected from the group consisting of barium sulfate, kaolin, diatomaceous earth, talc, each of which has been subjected to dehydrating treatment, silica, quartz sand, barite, alumina, titanium dioxide and iron oxides with a water-swellable thermoplastic resin, thereby forming a resultant blend;    thereafter heat-melting the resultant blend, thereby forming a molten blend;    extruding the molten blend through an extruder into the form of strand; and    continuously cutting the strand.    
     
     
         2 . A process for producing a bioreactor carrier, the specific gravity of which on swelling in water is controlled within the range of 1.02 to 1.35, comprising: 
 blending at least one inorganic filler selected from the group consisting of barium sulfate, silica, kaolin, quartz sand, diatomaceous earth, barite, talc, alumina, titanium dioxide and iron oxides at the time of producing a water-swellable thermoplastic resin from reactants of said resin, thereby forming a resultant blend of the at least one inorganic filler and the water-swellable thermoplastic resin;    thereafter heat-melting the resultant blend, thereby forming a molten blend;    extruding the molten blend through an extruder into the form of strand; and    continuously cutting the strand.    
     
     
         3 . A process for producing a bioreactor carrier, the specific gravity of which on swelling in water is controlled within the range of 1.02 to 1.35, comprising: 
 blending at least one inorganic filler selected from the group consisting of barium sulfate, silica, kaolin, quartz sand, diatomaceous earth, barite, talc, alumina, titanium dioxide and iron oxides at the time of producing a water-swellable thermoplastic resin from reactants of said resin, thereby forming a resultant blend of the at least one inorganic filler and the water-swellable thermoplastic resin;    further blending said at least one inorganic filler with the resultant blend with the proviso that any of barium sulfate, kaolin, diatomaceous earth and talc, when being added thereto, is subjected to dehydrating treatment in advance, thereby forming a further blend;    thereafter heat-melting the further blend, thereby forming a molten blend;    extruding the molten blend through an extruder into the form of strand; and    continuously cutting the strand.