Light weight medium for growing microorganisms

Abstract

A light weight medium for growing microorganisms includes a mass of polymeric foam, such as a polyurethane foam, having an outer region enclosing an inner region. A plurality of fragments of an inorganic material, such as sand, are at least partially embedded in the outer region. The light weight medium may be used to support growth of microorganisms in a wide variety of biological and/or biochemical processes, or may be used without microorganisms in chemically treating wastes.

1 . A method for producing a carrier for supporting microorganism growth, comprising the steps of: 
 providing a plurality of fragments of an inorganic material;    providing a mass of a less than fully cured polymeric foam; and    applying the plurality of fragments to an outer region of the mass of polymeric foam, wherein:    a core enclosed by the outer region contains none of the fragments; and    said applying step is performed such that the fragments are irregularly distributed in and on the outer region.    
   
   
       2 . The method of  claim 1 , further comprising the steps of: 
 selecting a polyurethane foam as the polymeric foam; and    selecting sand having a particle size of from about 0.2 mm to about 2 mm as the fragments of inorganic material.