Abstract: The invention concerns the unclogging of a hollow fibre filter operating in frontal mode. Said filter comprises a filter body (1) maintaining the hollow fibres (9) in a vertical position, the liquid to be filtered being introduced into the volume of the filter body (1) via the bottom, the filtrate being evacuated via the top of the filter. The unclogging comprises a reverse injection of gas into the hollow fibres (9) and a circulation of unclogging liquid in the volume of the filter body (1), said circulation of liquid taking place from the top towards the bottom of the filter body.

Abstract: The invention relates to a process for separating sodium from aqueous effluents resulting from the reprocessing of spent nuclear fuel elements. According to the invention, the effluent (3) is introduced into a tangential filtration module (11), whose membranes are made from polyaramide, sulphonated polysulphone or perfluorinated ionomer, so as to collect a permeate P containing sodium, depleted in radioactive elements and a retentate R enriched in radioactive elements.

Abstract: Process of continuously separating electrically charged, solid pulverulent materials in the form of a suspension in an electrophoresis and electroosmosis cell, characterized in that a fraction of the catholyte is drained off, that a portion thereof is treated with an acid, preferably gaseous, agent, that the treated portion is re-introduced into the cathode compartment, whereas the other part of the drained-off fraction is eliminated.The acid treatment is effected during continous pH measurements on the drained-off fraction of the catholyte.

Abstract: Process for the production and extraction of polysaccharides from a porphyridium cruentum culture and apparatus for performing the process.This production and extraction process comprises a stage of concentrating the polysaccharides consisting of leaving the culture medium (1) in a photoreactor (22) exposed to sunlight under stagnant conditions and at ambient temperature, leading to the formation of a polysaccharide-rich cream (23) and recovering said cream by skimming, a stage (24) of heating the concentrate obtained at a temperature between 60.degree. and 100.degree. C., a stage of separating the solid and liquid phases formed (26), a stage (30) of precipitating the polysaccharides contained in the liquid phase and a stage (16) of drying the precipitate obtained.