Abstract: A process for producing a solution of a gas in a liquid in which the gas is soluble, the solution having a predetermined concentration up to saturation. The gas and the liquid are brought together under controlled supply in a proportion corresponding to the predetermined concentration of the solution, and the gas and the liquid are caused to form a stream passing through a common conduit. The gas and the liquid in the stream are caused to intermix under the action of gravity, and the intermixing is repeated before the gas and the liquid have separated, so that the gas is substantially absorbed in the liquid, forming a gas-liquid solution of the predetermined concentration. The stream may be brought into turbulence for intensifying the intermixing of the gas and the liquid. An apparatus for performing the process includes a conduit including a continuous tubular coil formed with a plurality of upwardly and downwardly directed sections.

Abstract: A process for reclaiming spent selenium filter mass containing an inert material. The spent mass is treated with a hydrogen peroxide solution for leaching out selenium content from unspent active substance present in the filter mass to form selenious acid. The filter mass is treated with aqua regia solution to dissolve mercury selenide present in the mass. The aqua regia solution is separated from the mass and isolated. Suitably, the filter mass, which now contains inert carrier material, is transferred with the isolated selenious acid, to production of new selenium filter mass. After partial neutralization of the aqua regia solution, mercury is precipitated out for disposal. Before this, elemental selenium can be separated from the aqua regia solution by adjusting the pH level and used advantageously for production of new filter mass. Thusly, reclaimed selenium content and inert carrier material can be advantageously used for production of new selenium filters.

Abstract: A process for producing a solution of a gas in a liquid in which the gas is soluble, the solution having a predetermined concentration up to saturation. The gas and the liquid are brought together under controlled supply in a proportion corresponding to the predetermined concentration of the solution, and the gas and the liquid are caused to form a stream passing through a common conduit. The gas and the liquid in the stream are caused to intermix under the action of gravity, and the intermixing is repeated before the gas and the liquid have separated, so that the gas is substantially absorbed in the liquid, forming a gas-liquid solution of the predetermined concentration. The stream may be brought into turbulence for intensifying the intermixing of the gas and the liquid. An apparatus for performing the process comprises a conduit including a continuous tubular coil formed with a plurality of upwardly and downwardly directed sections.

Abstract: A process for reclaiming spent selenium filter mass containing an inert material, following take-up of mercury by a substance which contains selenium and is present in the filter mass. The spent mass is treated with a hydrogen peroxide solution for leaching out of the selenium content in essentially all unspent active substance present in the mass to form selenious acid. The resulting selenious acid is separated and isolated for use. The mass freed of the solution is treated with aqua regia for dissolving essentially all of the mercury selenide present in the mass. The aqua regia solution with its content of mercury and selenium are separated from the mass and isolated. Suitably, after it has been washed and dried, the mass freed of the aqua regia solution, which now only contains inert carrier material, and also the previously isolated selenious acid, are transferred to production of new selenium filter mass.