Aerobic biological dehalogenation reactor

DETAILED DESCRIPTION In accordance with the present invention, a biological reactor for dehalogenating and biodegrading waste organic compounds present in a water mixture (liquid phase) has a mixed microbial population including methylotrophic microorganisms supported on a solid substrate bed in a reactor housing.
The substrate bed is preferably made of a manufactured solid material, such as activated carbon particles, having a larger specific surface area and less resistance to hydraulic flow therethrough than natural materials such as soil.
In one preferred form of this invention, a low-molecular-weight alkane is flowed through the liquid phase either prior to or in the bed to provide a carbon and energy source for the methylotrophic microorganisms.
The flow rate of the low-molecular weight alkane is preferably sufficient to maintain at least a minimum concentration of the alkane throughout the substrate bed.
In reactors containing a significant population of methanotrophic microorganisms (a sub-class of methylotrophic microorganisms), the low-molecular-weight alkane is substantially methane.
In addition to the low-molecular-weight alkane, a second gas consisting at least partially of oxygen is also flowed through the liquid phase either prior to or in the bed.
The flow rate and oxygen concentration of the second gas is preferably sufficient to achieve at least a minimal concentration of dissolved oxygen to maintain aerobic conditions substantially throughout the bed.
The aqueous liquid mixture containing halogenated and other organic compounds is passed through the bed wherein the microorganisms aerobically metabolize the organic compounds in the mixture along with the low-molecular-weight alkane.
Such metabolism includes co-metabolic processes that dehalogenate, including dechlorinate, the organic compounds in the liquid mixture.
As another aspect of the invention, the solid substrate bed may be formed of activated carbon granules which are preloaded with organic compounds, or which are entirely "spent" with regard to adsorptive capacity