Quantum Mechanical Density Functional Theory Simulation of Detoxification of Hexavalent Chromium Metal Ion of All Types of Chrome Industry Effluents

Abstract

Hexavalent chromium ion, Cr(VI) is highly toxic. Effects of Cr(VI) are irritation of the nose and eyes, skin allergy, kidney problems, and liver and stomach damage. Its presence up to 1500ppm is proven in effluents of leather-tanning, chrome-plating, and metal-extraction industries. Being dangerous, either the toxic Cr(VI) is to be converted into the less toxic Cr(III), or Cr(VI) is to be completely removed from the effluent water before discharging into the river or ocean. Both methods of detoxification of chrome industry effluent are reviewed. The redox method of converting hexavalent chromium ions into trivalent chromium ions before discharging effluent water into the river. The redox conversion of Cr(VI) to Cr(III) is experimentally analyzed with an example. And, the adsorption method of removing fully hexavalent chromium by adsorption in polymer polyaniline (PANI) or polyaniline / bacterial cellulose (PANI / BC) nanocomposite, Cr(VI) adsorption on PANI is theoretically analyzed. The density functional method is used to simulate the adsorption process and evaluate the adsorption efficiency. Under acidic conditions, the Cr(VI) removal capacity is higher than that under alkaline conditions. It is observed both in the redox process and in the adsorption method.