Process for the separation of Cu++ -ions from sewage, waste water and aqueous solutions

Claim 1

A process for the separation of Cu ++ -ions from an aqueous liquid in which said Cu ++ ions exist as complexes of ethylenediamine tetraacetic acid and/or diethylenetriamine pentaacetic acid or their anions, comprising contacting said liquid with an HS-containing triazine compound of the general formula ##STR4## in which: R is hydrogen, the same or different alkyl with 1 to 3 carbons, --NR 1 R 2 or --OR 3 ; R 1 , r 2 and R 3 are hydrogen, the same or different alkyl with 1 to 6 carbons or phenyl; n is a whole number from 0 to 2, or of a water soluble salt to precipitate said Cu ++ ions, and wherein said compound is contacted in an amount such that at least one equivalent of mercapto or mercaptide groups is present per equivalent of said Cu ++ ions and the precipitation of the Cu ++ -ions takes place in the presence of an at least equivalent quantity of Fe +++ -ions, related to the complexing agent content in the liquid, and at a pH value between 4 and 10, and separating the precipitate from the aqueous liquid.