NOVELTY - A medium (1) for treating wastes, comprises a mass of polymeric foam (3) having an outer region surrounding a core; and fragments of inorganic material (2) comprising activated carbon, pure elemental fragments, clay, limestone, or iron salts, where a first portion of the fragments is adhered only to the outer surface of the outer region, and a second portion of the fragments is partially embedded in the outer region.    USE - The medium is for treating wastes (claimed). It is used to support growth of microorganisms in biological and/or biochemical processes. It is used as a solid carrier for catalyzing chemical reactions and/or neutralizing acidic wastes. It is for use in industries, e.g. wastewater treatment, production of organic compounds in bioreactors, gas separation, biofilters, remediation of hazardous waste, water treatment, and production of fermented products. It is useful in distillation, airscrubbing towers, flue gas scrubbers, animal waste treatment, aquarium treatment systems, pharmaceutical manufacturing, odor control at wastewater treatment plants (e.g. in a biofilter at the headworks of the plant) or manufacturing plants, fluidized beds, catalytic beds, and storm water treatment.    ADVANTAGE - The medium is lightweight and so cheap to transport. It does not require an increasingly higher inflow pressure to overcome pressure losses created by the microbes populating the media; does not settle out of a suspended growth process during periods of low flow; and retrofits the suspended growth process. It is stable over time and will not decompose, rot, or change dimensions; and is inexpensive, dependable, and fully effective.    DETAILED DESCRIPTION - A medium (1) for treating wastes, comprises a mass of polymeric foam (3) having an outer region surrounding a core; and fragments of inorganic material (2) comprising activated carbon, pure elemental fragments, clay, limestone, or iron salts, where a first portion of the fragments is adhered only to the outer surface of the outer region, and a second portion of the fragments is partially embedded in the outer region. Substantially none of the fragments are contained within the core.    DESCRIPTION OF DRAWING(S) - The figure is a cross-sectional view of a mass of polymeric foam with granular material embedded in an outer region.    Medium (1)    Inorganic material (2)    Polymeric foam (3)