INTRAVAGINAL FEEDING SYSTEM, ITS USE AND PROCESS FOR PRODUCING THEREOF

摘要

PCT No. PCT/FI94/00262 Sec. 371 Date May 17, 1996 Sec. 102(e) Date May 17, 1996 PCT Filed Jun. 16, 1994 PCT Pub. No. WO95/00446 PCT Pub. Date Jan. 5, 1995A method for the treatment of sludge obtained from such a water treatment process wherein an aluminium or iron chemical is used as a coagulant, so as to reduce the amount of sludge, which method comprises the steps of: a) treating the water treatment sludge with an inorganic acid to produce an acidic sludge comprising dissolved aluminium or iron, b) optionally separating insoluble material from the acidic sludge to produce an acidic solution comprising dissolved aluminium or iron, c) treating said acidic sludge or said acidic solution with a +1-cation compound in the presence of sulphate ions in such conditions that the pH of the sludge or solution remains at a level where aluminium precipitates as an alunite compound or iron precipitates as a jarosite compound, and d) separating the precipitated alunite or jarosite compound from the remaining sludge.