Copper separation using modified active carbon before the polarographic determination of Pb, Cd, Ni, Zn and Fe in wastes

The investigations on the selective separation of Pb2+, Cd2+, Ni2+, Zn2+ and Fe3+ ions from the excess of copper were carried out. For this purpose active carbon modified by Na-diethyldithiocarbamate was used. The manner of DDTK-Na deposition on active carbon has been elaborated. The influence of pH was investigated and it was found that at pH 1(HNO3) copper ions are quantitavely bound on modified carbon whereas other ions (Pb2+, Cd2+, Ni2+, Zn2+ and Fe3+) remain in the solution and can be determined polarographically. The elaborated method was applied to the determination of mentioned ions in the samples of wastes containing even 100-fold excess of copper. The concentration of copper can not exceed 100 mg/dm3. (author)