Process for the detoxification treatment of hazardous wastes

摘要

A process for producing a non-hazardous sludge from an aqueous solution which contains heavy metals comprising the steps of: (a) adding phosphoric acid or an acid phosphate salt to the aqueous solution to percipitate the heavy metals; (b) lowering the pH of the solution to less than about 5.0; (c) adding a coagulant to the solution; (d) raising the pH of the solution to above about 7.0 by the addition of a calcium source; and (e) dewatering the resulting non-hazardous sludge.