Adsorption and subsequent detoxification of hexavalent chromium in aqueous solution using polypyrrole‐bacterial extracellular polysaccharide nanocomposite

Abstract

The aim of this study was to assess the adsorption and Cr(VI) detoxification potential of polypyrrole-bacterial extracellular polysaccharide (PPy-EPS) nanocomposite. The nanocomposite was synthesized by in situ chemical oxidative polymerization of pyrrole monomer with bacterial extracellular polysaccharide (EPS). Scanning and transmission electron micrographs showed the nanocomposites to be irregular in shape and mostly present in aggregates. Fourier transform infrared analyses illustrate the characteristic peaks (2934, 1548, 1463, and 1165 cm 21 ) of both pyrrole and bacterial extracellular polysaccharides. X-ray diffractogram showed the amorphous nature of the nanocomposite, and the surface area of the PPy-EPS nanocomposite was measured as 26.21 m 2 g 21 . The nanocomposite efficiently reduced more than 80% of Cr(VI) within 30 min. The X-ray diffractogram corresponding to the crystal planes ( (012), (110)) of Cr 2 O 3 further confirmed the reduction of Cr(VI). The results of the study confirm PPy-EPS nanocomposite as suitable option for the treatment of Cr(VI)-bearing industrial wastewaters.

Chromium Pollution in European Water, Sources, Health Risk, and Remediation Strategies: An Overview

“…It has been demonstrated that bacteria can facilitate the removal of metal species from aquatic solutions owing to adsorptive properties of their cellular surface [ 138 , 139 , 140 ]. The biosorption of heavy metal ions by microorganisms is influenced by several parameters including specific surface properties of the microorganism (biosorbent), the amount of biomass, physico-chemical parameters of the solution such as temperature, pH, initial metal ion concentration, and the existence of other ions [ 141 ].…”

Biosynthesis of Cr(III) nanoparticles from electroplating wastewater using chromium-resistant Bacillus subtilis and its cytotoxicity and antibacterial activity

“…Cr(VI), on the other hand, is highly toxic than Cr(III) and causes liver damage, pulmonary congestion, epigastric pain, skin ulcers, and mutation and cancer in humans (Baruthio 1992). It is also highly mobile than Cr(III) (Rajeswari et al 2016). Because of high toxicity, World Health Organization recommends maximum permissible limit of Cr(VI) in drinking water to be 0.05 mg/l, with no relaxation on the permissible limit (WHO 1993).…”