Removal of Cu(II) from dilute solutions at polypyrrole modified electrodes

The removal of Cu2+ ion from dilute acidic solutions containing dissolved oxygen was investigated through its spontaneous and potentiostatic reduction at Pt and reticulated vitreous carbon (RVC) electrodes recovered with reduced polypyrrole (PPy0). it was observed that the spontaneous Cu2+ ion reduction occurs only at the Pt/PPy0 electrode. In the electroreduction procedure, a removal efficiency of 99.8% was achieved with the RVC-PPy0 electrode after 30 min of electrolysis at -0.40 V vs. a saturated calomel reference electrode. The removal efficiency of Cu2+ ion from the solution was evaluated by monitoring its concentration decay through linear voltammetric measurements at a Pt ultramicroelectrode and/or by flame atomic absorption spectrometry. Due to its high efficiency and simplicity, the electroreduction procedure at the RVC-PPy0 electrode may become advantageous in the removal of low-level concentrations of copper from pretreated industrial wastes.