(US5551987-A)      A process for treating solid waste or mud contaminated by oily hydrocarbon residues, which process consists of:    (a) extracting oily hydrocarbon residues from the solid waste or mud, at least once at 40-110 C., using a non-volatile organic solvent, thereby forming an oily supernatant phase and a solid phase, the ratio of organic solvent to oily hydrocarbon residues being 0.1-3:1;    (b) contacting the oily supernatant phase with a mixture of microbes which oxidize hydrocarbons and microbes which produce high levels of biosurfactant, so as to form a bio-oxidized solution; and    (c) washing the solid phase formed in step (a) with a bio-oxidized solution selected from the group consisting of (i) the solution formed in step (b) and (ii) a culture broth comprising the mixture of microbes used in step (b), the ratio of bio-oxidized solution to solid phase being 5-15:1.    (EP656234-B1)      Process for the treatment of solid waste and mud contaminated by oily residues consisting of the following steps: (a) pre-treatment at 40-110 deg.C by at least one extraction with a non-volatile organic solvent in a ratio 0.1-3:1 with the hydrocarbons to separate the oily phase from the solid residue; (b) washing of the solid residue resulting from step (a) with a supernatant liquid resulting from step (c) in a ratio 5-15:1 with said solid residue; (c) bioxidation of the washing medium using an oxidating hydrocarbon microbic mixture and a high producer of biosurfactant.    (RU2123979-C1)      Solid waste and mud contaminated by oily residues are treated by (a) pre-treatment at 40-110 deg. C by at least one extraction with a non-volatile organic solvent (S) in ratio 0.1:1 to 3:1 with the hydrocarbons in the waste, to separate the oily phase from the solid residue (R); (b) washing (R) with a supernatant liquid (L) resulting from step (c), in ratio (L):(S) 5:1 to 15:1, and (c) bio-oxidising the washing medium using a hydrocarbon-oxidising microbic mixture which is a high producer of surfactants.    USE -   The materials treated are wastes from the oil and petrochemical industries, and ground accidentally contaminated with hydrocarbons.    ADVANTAGE -   Recycling and recovery of hydrocarbons is maximised. Bio-oxidation is facilitated as the hydrocarbons are present in dissolved or dispersed form; conventional bioreactors can be used as no solid phase is present, and biological processing may be continuous. Surface activity of the fermentation broth is utilized. Residence time in the bio-processing is reduced from the ca.30 days of the prior art to 0.5-1 days, and handling is easier.