Method and apparatus for bioremediation of mixed hazardous wastes

摘要

A method and apparatus for bioremediation of mixed hazardous waste is discussed. The method and apparatus can be used for treatment of a liquid or slurry hazardous waste stream (e.g., industrial wastewater or sludge) or for treatment of contaminated groundwater. Removal of the following constituents is possible: (1) aromatic hydrocarbons, such as benzene, toluene, ethylbenzene, xylenes, phenols and cresols, (2) halogenated (e.g. , chlorinated) hydrocarbons, such as tetrachloroethylene, trichloroethylene, 1,1,1-trichloroethane and similar xenobiotics, (3) heavy metals, such as copper, lead, zinc, lead, mercury, cadmium, and chromium, (4) acids, such as sulfuric acid and nitric acid, and (5) salts, such as sulfates and nitrates. One embodiment of the invention involves the steps of denitrification (e.g., nitrate reduction), sulfate reduction, methanogenesis and aerobic respiration. Other embodiments delete the denitrification, sulfate- reduction or aerobic respiration steps. In a preferred embodiment, at least a portion of the denitrification and/or sulfate-reduction steps occur in a suspended continuous culture reactor under kinetic control, while the methanogenesis may occur in a biofilm (e. g., in a packed bed reactor or in situ underground.) Reductive dechlorination, control of pH, energy conservation and control of air pollution are accomplished.