Water pollution by heavy metals is a great health concern worldwide. Lead and cadmium are among the most toxic heavy metals because they are dangerous for the human and aquatic lives. In this work, the removal of lead and cadmium from aqueous solutions has been studied using electrosynthesized 4-amino-3-hydroxynaphthalene-1-sulfonic acid-doped polypyrrole (AHNSA-PPy) films as a new adsorbent. Two distinct methods, including the immersion method, based on the Pb2+ and Cd2+ spontaneous removal by impregnation of the polymer in the solution, and the electro-elimination method, consisting of removal of Pb2+ and Cd2+ ions from the solution by applying a small electrical current (5 mA) to the polymer film, were developed: the evolution of Pb2+ and Cd2+ concentrations with time was monitored by inductively coupled plasma optical emission spectrometry (ICP-OES). The effect of pH on the adsorption and electro-elimination of Pb2+ and Cd2+ using the AHNSA-PPy film was investigated and optimized, showing that the ionic adsorption and electro-elimination processes were highly pH-dependent. The kinetics of Pb2+ and Cd2+ adsorption and electro-elimination were found to follow second-order curves. The maximum adsorption capacity values of the AHNSA-PPy film were 64.0 and 50.4 mg/g, respectively, for Pb2+ and Cd2+. The removal efficiency values were, respectively, for Pb2+ and Cd2+, 80 and 63% by the immersion method, and 93 and 85% by the electro-elimination method. Application of both methods to Senegal natural waters, fortified with Pb2+ and Cd2+, led to removal efficiency values of, respectively for Pb2+ and Cd2+, 76–77 and 58–59% by the immersion method, and of 82–90 and 80–83%, by the electro-elimination method.
Jiang N, Xu Y, Dai LW, Dai L (2012) Polyaniline nanofibers assembled on alginate microsphere for Cu2+ and Pb2+ uptake. J Hazard Mater 215–216:17–24CrossRefGoogle Scholar
Jin X, Ling-jun L, Chen W, Xiao-feng W, Wen-yu F, Li-hong X (2008) Lead induces oxidative stress, DNA damage and alteration of p 53, Bax and Bel-2 expressions in mice. Food and Chem Toxicology 46:1488–1494CrossRefGoogle Scholar
Poey J, Philibert C (2000) Toxicité des métaux. Rev Fr Lab 323:35–43Google Scholar
Ramesh ST, Gandhimathi R, Badabhagni N, Nidheesh PV (2011) Removal of Cd (II) from aqueous solution by adsorption onto coir pith, an agricultural solid waste: batch experimental study. Environ Engin Manag J 10:1667–1673Google Scholar
Sall ML, Diaw AKD, Gningue-Sall D, Chevillot-Biraud A, Oturan N, Oturan MA, Aaron J-J (2017) Removal of Cr (VI) from aqueous solution using electrosynthesized 4-amino-3-hydroxynaphthalene-1-sulfonic acid doped polypyrrole as adsorbent. Environ Sci Pollut Res 24(26):21111–21127. https://doi.org/10.1007/s11356-017-9713-yCrossRefGoogle Scholar