Abstract: Methylotrophic and heterotrophic microorganisms are supported on a rigid substrate bed. Oxygen, such as from air, and a low-molecular-weight alkane, such as methane, flow through the bed. Organic compounds in contaminated water processing through the bed are biodegraded by the microorganisms. The bed may be formed of manufactured particlate material, such as of activated carbon. These bed-forming materials may be preloaded with organic carbon materials to provide a nutrient source for the microogranisms. The biological reactor may continuously treat effluent from, for example, an industrial plant, in either a batch or continuous process. A water solids removal subsystem may be positioned upstream of the biological reactor to remove organic carbon compounds and various solids from the contaminated water prior to treatment. Optional bed cleaning mechanisms may also be included in the biological reactor.

Abstract: A method and apparatus are disclosed for dehalogenating and further biodegrading organic compounds, including halogenated organic compounds, present in an aqueous mixture, the mixture comprising the waste effluent produced in a continuous high flow rate by an industrial plant such as a bleach pulp or paper mill using chlorine and chlorine compounds. The aqueous mixture is passed through at least one combination of a first oxygen-enriched liquid zone and a second zone containing a mixed population of methylotrophic and heterotrophic microorganisms supported on a substrate bed. A first gas including oxygen is flowed through the first zone and second gas consisting substantially of a low-molecular-weight alkane is flowed through the second zone as the aqueous mixture passes through the first and second zones.