Waste from electrical and electronic equipment (WEEE) represents a valuable source of key materials essential in strategic sectors. This study investigates the adsorption of metal ions from a real complex leachate solution from milled printed circuit boards of mobile phone. The complex multi-ions leachate is exposed to two different sorbents, clay and activated carbon, both when pristine and modified with pentaethylenehexamine, while maintaining a fixed solid/liquid ratio equal to 0.04 g/mL. The findings indicate the different behaviour of the sorbents towards the various ions. All the sorbents show the same uptake efficiency (100%) towards tin (Sn), while a different behaviour is displayed towards the uptake of copper (Cu): pristine clay reaches almost 1% of efficiency, while the other sorbents exceed 50%. The leachate solution exhibits an extremely high concentration of Cu (90%), thus, to reduce the amount of metal ions present in solution, a copper electrodeposition step is performed. The obtained new solution results in a more balanced and homogeneous composition. The adsorption performed on the new solution reveals an increase of total metal ion uptake up to 80%.