Abstract: Adsorbents suitable for use to remove aromatic or polyaromatic hydrocarbons from liquids such as oils may be produced from an acid-activated siliceous clay containing adsorbed oil by treating to carbonize the oil and to activate the carbon so produced on the surface of the clay. The carbonization and activation steps may be conducted by heating in the presence of an activating agent which may be zinc chloride. Preferably zinc chloride activated material is subsequently steam-treated.The invention is particularly useful to reduce the content of hazardous polyaromatic hydrocarbons, such as benzo(a)pyrene, from edible oils.

Abstract: Unless aqueous acidic hydrogen peroxide solutions are stabilized, an excessive rate of decomposition of hydrogen peroxide precludes their use for treatment of metal surfaces, such as of copper and copper alloys, during which use substantial concentrations of decomposition catalysts build-up in solution. Regular monitoring of the solutions for residual stabilizer content would demand sophisticated analytical equipment beyond the reach of many users.The invention provides a stabilizer in the form of a block of sparingly soluble material, whereby monitoring can be simply and readily effected visually or by a simple electrical or mechanical detection system. For copper/copper alloys preferred stabilizers are p-hydroxybenzoic acid and triphenyl carbinol.

Abstract: Organic sulphides are extremely malodorous compounds that are found in gaseous or aqueous effluents from many industries such as paper and pulp manufacture, hydrocarbon refinering, tanneries, and in the synthesis of organic sulphur compounds. Their removal is necessary before such effluents can be discharged into the environment.In the present invention their removal is effected using hydrogen peroxide at a pH controlled to pH 8.5 to 11.5 and in the presence of a catalytic amount of a soluble tungstate. Such a process is especially applicable to the removal of dialkyl disulphides, which are regarded as being especially difficult to remove oxidatively. In especially preferred conditions, the pH is about pH 11 and about 3-4 moles H.sub.2 O.sub.2 is used per mole equivalent of sulphur, in the presence of at least 20 ppm sodium tungstate (as W).

Abstract: The invention relates to the preferential precipitation of cobalt from aqueous acidic sulphate solutions of nickel and cobalt.The separation is carried out by introducing at least a stoichiometric amount of Caro's Acid containing no more than a small amount of hydrogen peroxide into the nickel/cobalt solution progressively over a period of at least an hour, while maintaining the solution of a pH from 3.1 or 3.5 up to 4.7 by addition of an alkali metal hydroxide carbonate or bicarbonate, or at 4.3 to 4.7 with the corresponding ammonium compound, and, thereafter separating the precipitate from the aqueous cobalt depleted solution.