Biological and hazardous sludges and slurries represent a major disposal problem. Dewatering is a major cost element. This two-step technology involves a first step achieving essentially complete dewatering in a backmix reactor by dispersion of sludge in heavy oil reaction media maintained at water vaporization temperature using energy efficient vapor recompression. The oxidizables in the vapor phase are catalytically oxidized, conditioning the dry solid residuals for the second step, a light alkane counter current extraction of hydrocarbon residuals from the solids. Innovatively, the vapor state oxidation yields condensate quality water, and the oil bath reactor/extractor removes toxic hydrocarbons from solids. The resulting treatment system, therefore, is a generic process for dewatering/detoxi-fication of sludges and slurries that is totally enclosed and yields three products: a purified distilled water, extracted oils/greases, etc., and de-oiled and dried solids.Anticipated results of this research will define the design of equipment for the transition from the evaporator to the extractor of a prototype unit providing the most efficient and cost- effective operation. This generic process technology provides dewatering/detoxifying/sterilization treatment for a wide variety of slurries and sludges: bio-sludges for recycle as soil amendment, complete recovery for recycle values in rolling mill sludges, detoxification of PCB contaminated wet solids, etc.
