Electrochemical-switchable polymer film: An emerging technique for treatment of metallic ion aqueous waste

The present work aims at using grafted polyacrylic acid (PAA) films as active surfaces for heavy metal waste removal. We focus first on grafting PAA onto carbon felt surfaces by means of an economical and simple preparation method compatible with real industrial applications. XPS, SEM results and interfacial electrochemistry allow us to confirm the grafting of PAA films on carbon felts. Metal ion uptake inside the PAA film is discussed in detail. The final part of the work is then devoted to the application of carbon felt grafted PAA electrodes to remove metal ions from aqueous waste according to the electrochemical-switchable process. Primary treatments of real industrial effluents are performed with a lab-made semi-pilot system. Such electrochemical-pH-switchable PAA films can be considered within the field of aqueous effluent treatments in order to reach very low concentration in heavy metal ions.