2. Academic Validation
  3. Removal of Cr(VI) from aqueous solution using electrosynthesized 4-amino-3-hydroxynaphthalene-1-sulfonic acid doped polypyrrole as adsorbent

Removal of Cr(VI) from aqueous solution using electrosynthesized 4-amino-3-hydroxynaphthalene-1-sulfonic acid doped polypyrrole as adsorbent

  • Environ Sci Pollut Res Int. 2017 Sep;24(26):21111-21127. doi: 10.1007/s11356-017-9713-y.
Mohamed Lamine Sall 1 2,  Abdou Karim Diagne Diaw 1,  Diariatou Gningue-Sall 1,  Alexandre Chevillot-Biraud 3,  Nihal Oturan 2,  Mehmet Ali Oturan 2,  Jean-Jacques Aaron 4
Affiliations

Affiliations

  • 1 Laboratoire de Chimie Physique Organique et d'analyse Instrumentale, Département de Chimie, Université Cheikh Anta Diop, Dakar BP 5005, Dakar-Fann, Senegal.
  • 2 Laboratoire Géomatériaux et Environnement, Université Paris-Est, EA4508, UPEM, 77454, Marne la Vallée, France.
  • 3 Interfaces, Traitements, Organisation et Dynamique des Systèmes (ITODYS), Université Paris 7-Denis Diderot - CNRS - UMR 7086, Bâtiment Lavoisier, 15 rue Jean de Baïf, 75205, Paris Cedex 13, France.
  • 4 Laboratoire Géomatériaux et Environnement, Université Paris-Est, EA4508, UPEM, 77454, Marne la Vallée, France. jeanjacquesaaron@yahoo.fr.
PMID: 28730362 DOI: 10.1007/s11356-017-9713-y
Abstract

Polypyrrole (PPy) conducting films, doped with 4-amino-3-hydroxynaphthalene sulfonic acid (AHNSA), were electrosynthesized by anodic oxidation of pyrrole on Pt and steel electrodes in aqueous medium (0.01 M AHNSA +0.007 M NaOH, using cyclic voltammetry (CV), and their electrochemical properties were studied. Fourier-transform infrared (FT-IR) spectroscopy confirmed the formation of AHNSA-PPy films. Their morphology was characterized by scanning electron microscopy (SEM), and their optical properties, including UV-VIS absorption and fluorescence spectra, were also investigated. AHNSA-PPy films were used for the removal of chromium(VI) from aqueous solution, by means of the immersion method and the Cr(VI) electro-reduction method. The effect of various experimental parameters, including the adsorbent (polymer) mass, pH, type of electrodes, and current intensity, on the adsorption of chromium by the polymer was performed and optimized. The adsorption and electro-reduction of (Cr VI) on the AHNSA-PPy film surface were found to be highly pH-dependent, and the kinetics of Cr(VI) adsorption and electro-reduction followed second-order kinetic curves. Apparent second-order rate constants were about three times higher for the Cr(VI) electro-reduction method than for the immersion method, indicating that the use of electro-reduction method significantly accelerated the chromium adsorption process on polymer. The maximum adsorption capacity of the AHNSA-PPy film for chromium was 224 mg g-1. A 96% chromium removal from pure aqueous solution was reached within about 48 h by the immersion method, but only within about 6 h by the Cr(VI) electro-reduction method. Application of both methods to Cr(VI) fortified natural waters of Senegal led to chromium removal efficiency high values (93 to 96% according to the type of natural water).

Keywords

4-Amino-3-hydroxynaphthalene sulfonic acid (AHNS)-polypyrrole films; Adsorbent; Electro-reduction; Hexavalent chromium removal.

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