Several industrial sectors such as surface treatment, petroleum, chemical, etc. generate effluents containing heavy metal ions (HMI). The main metal ions in such effluents can be zinc, copper, vanadium, etc. Purification of such effluents by magnetic separation is performed by adding a certain proportion of iron salts. These salts precipitates together with those of HMI by increasing the pH. The coprecipitation of this "magnetic carrier" with heavy metals hydroxydes to create a magnetic flee has been studied. The effluent treated passes by a superconducting separator where the flocs are retained in a matrix of steel wires. The purified effluent leaves the separator, and the trapped flocs are collected when the matrix is saturated. The efficiency of HMI separation by this method exceeds 95%.