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Title: Bio-slurry reaction system and process for hazardous waste treatment

Patent ·
OSTI ID:6190892

A method is described for improved slurry-phase bioremediation treatment of organic sludge and mixtures of organic sludge and organic-contaminated soils by dissolving the contaminants into an aqueous phase and microbially degrading same; comprising the steps of: (a) forming a high solids slurry of the sludge and soils with water and an active bioslurry consisting of large populations of acclimated hydrocarbon-utilizing bacteria and small amounts of biodegradation residue; the bacteria being selected from the genera Pseudomonas and Acinetobacter, and being capable of producing extracellular long-chain hydrocarbon-emulsifying and hydrocarbon-solubilizing agents for decreasing aqueous surface tension and lowering interfacial tension between oil and water; (b) passing the high solids slurry through a plurality of in-series bioreactors in each of which a low hydraulic shear is maintained to promote the development of a large population of microorganisms that will form flocculent suspensions; the first stage bioreactor in the series being a waste dissolution reactor operated under anoxic conditions to form a stable emulsion through the presence of the hydrocarbon-emulsifying and hydrocarbon-solubilizing agents produced by the bacteria; (c) continuously or semicontinuously flowing the output from the series of bioreactors to a liquid-solids separator to partition the mixed liquor bioslurry from the biodegraded waste residue; (d) returning the mixed liquor bioslurry containing small amounts of biodegradation residue to the slurry of step (a) for recycling; and (e) recirculating off-gas components from the system including one or more members of the group consisting of benzene, toluene, xylenes, and naphthalene back to one or more of the bioreactors, to return high volatility toxic constituents for increased microbial degradation and control of volatile toxic constituents emissions from the process.

Assignee:
Radian Corp., Austin, TX (United States)
Patent Number(s):
US 5232596; A
Application Number:
PPN: US 7-773344
OSTI ID:
6190892
Resource Relation:
Patent File Date: 7 Oct 1991
Country of Publication:
United States
Language:
English