Abstract: The invention relates to a decontamination process for a porous medium polluted by hydrocarbons according to a composition containing a surface active agent as glycolipids in their crude or modified form is introduced, for example by at least one input well, in the optional presence of hydrocarbon-destroying bacteria and at least one part of the composition containing at least one part of the hydrocarbons is collected, for example by a production well.

Abstract: A method and a device usable in particular for washing solid products contaminated by hydrocarbons.According to this method, a desorbent liquid phase is used to wash solid products which are brought into contact with this desorbent liquid phase forming a mixture consisting of solution, desorbed hydrocarbons and washed products. Said mixture, freed from gravel, undergoes at least one separation stage, this separation giving a underflow comprising at least the major part of the washed sand and an overflow from which the hydrocarbons and the aqueous phase are recovered.This method is applicable to de-oiling oil-contaminated sands and gravels.

Abstract: A special trawl net for collecting floating products has a dorsal or upper face of a close-mesh netting which extends over the two wings of the trawl and forms on the ventral or lower face thereof two lateral strips separated by a central net zone having a wider-mesh netting, so that water can easily escape therethrough. An impervious sleeve surrounding the bag formed by the trailing end of the trawl, and extending beyond this trailing end, is connected to the bag at one end and is open at its other end. This sleeve makes it possible to sealingly enclose the bag when the latter is filled with the products to be collected.

Abstract: The system comprises a flexible line provided with means for collecting products scattered at the water bottom by circulating the flexible line in contact with these products. On the rising portion of the path followed by the flexible line, the collecting means are passed through a tubular casing for simultaneously protecting the surrounding water against pollution from products released, while hoisting the products to the surface.

Abstract: Process for absorbing hydrocarbons or organic solvents, particularly in solution or suspension in water at a low concentration, by means of an absorption mass consisting of rubber particles of from 0.1 to 3 mm, subjected to a treatment with an organic or inorganic acid or an aqueous solution or emulsion thereof.

Abstract: Surfaces and media contaminated with fatty materials such as hydrocarbons, vegetable or animal oils or fats, organic solvents and other organic compounds may be cleaned by spreading thereon leather particles and/or fibers. A preferred embodiment comprises bringing leather wastes to a selected water content and crushing them to particles and/or fibers.

Abstract: Catalytic oxidation of hydrogen sulfide to sulfur in homogeneous liquid phase, by means of molecular oxygen, in an organic solvent whose water content is lower than 60% by volume, said liquid phase comprising a solvent selected from amides, phosphoramides, sulfoxides, nitriles and ethers, said oxidation being conducted in the presence of at least one catalyst selected from the two following categories:A. a chelate of a transition metal selected from the group of metals consisting of iron, manganese, copper and cobalt, the chelate being selected from the group consisting of dialkyldithiocarbamates, alkylxanthates, dithiolates, 8-hydroxyquinolinates and salicylaldimines,B. a salt of said transition metal of the formula MX.sub.m in which M is the transition metal, X is an anion selected from the group consisting of Cl.sup.-, Br.sup.-, ClO.sub.4.sup.-, NO.sub.3.sup.- and SCN.sup.- and m is 2 or 3.