Studies of Chromium Removal Using Eco-Friendly Conducting Polymer/Biopolymer/Clay Nanocomposite

Environmental contamination by heavy metals is a common problem, with sources of pollution arising from industrial activities. Chromium is one of the most toxic heavy metalsgenerated by the electroplating, leather tanning and textile industries. In aqueous environment, chromium exists in twooxidation states, [Cr(III)] and [Cr(VI)]. But Cr(VI) is more hazardous, carcinogenic and mutagenic to living organisms. There are various methods to remove Cr(VI), such aselectrocoagulation, chemical reduction, ion exchange, and adsorption, etc. As one of the most promising techniques,adsorption technology has been employed for many years and the effectiveness of various adsorbents such as conducting polymers and biopolymers has been demonstrated [1].Polyaniline (PANI) is one of the most promising conducting polymers for the removal of dyes and heavy metals. Due to theimportance of environmental protection, new composite adsorbents combining PANI and biopolymers have attracted much attention [2]. Alginate (Alg) is a linear polysaccharide biopolymer and has a capacity to remove toxic pollutants. Also the clays such as montmorillonite (MMT) have beenwidely used as adsorbents of organic pollutants and the polymeric material modified with these clays significantly improves their capability to remove heavy metals from aqueous solutions [3].