Abstract: Disclosed herein is a method for the removal of organic and inorganic contaminants from contaminated sediment or soil. The method comprises a first step of removal and disposal of very large debris while the smaller particle flow is directed to a second step of removal of organic contaminants preferably by means of attrition cell, conditioning tank and flotation columns, the remaining particulate flow, free of organic contaminants, is directed to a third step of removal of inorganic contaminants preferably by means of hydrocycloning to separately deal with very small particles of less than 20 microns, both particulate flows are then preferably subjected to column flotation to separate out the inorganic contaminants. Thus, the method of the present invention yields decontaminated soil or sediment and two distinct contaminant concentrates (organic and inorganic, respectively). Both concentrates can be recovered and used for various applications.

Abstract: The present invention is concerned a process for the regeneration of the spent silica gel used in chromatography and for any other kind of silica. The process comprises 5 main steps, namely: washing with an extractant of organic compounds and removing volatile organic materials remaining thereafter; oxidation to oxidize organic compounds remaining and, preferably, bleach the material; washing with an acid to remove soluble inorganic matter; heating to dry the material and combust any remaining organic compounds present; and recovering the regenerated material. Various optional steps can be added to the process.