Assessment of polyphenol coated nano zero valent iron for hexavalent chromium removal from contaminated waters

Bull Environ Contam Toxicol. 2015 Mar;94(3):302-7. doi: 10.1007/s00128-014-1442-z. Epub 2014 Dec 16.

Abstract

Alternative plant extracts were examined as raw materials for the synthesis of nZVI from ferric solutions. Four plants were selected for evaluation, i.e. Camellia sinensis (green tea, GT), Syzygium aromaticum (clove, CL), Mentha spicata (spearmint, SM) and Punica granatum (pomegranate, PG). Based on the results obtained, it was concluded that the reduction of Fe(III) with the herb extracts is not complete. Using the GT extract, approximately 28 mM of the initial 66 mM of Fe (42.4 %) are reduced to the elemental state Fe(0). The highest reduction of Fe(III), about 53 %, was achieved with PG and the lowest, only 15.6 %, with the SM extract. Additional batch experiments have been carried out to evaluate the effectiveness of nZVI, synthesized with GT, CL, SM and PG, for the removal of hexavalent chromium from a 0.96 mM solution. The highest reduction of Cr(VI) (96 %) was obtained using the nZVI suspension produced with PG juice. The other three nZVI suspensions, i.e. CL-nZVI, GT-nZVI, and SM-nZVI, had a comparable effectiveness corresponding to 70 % reduction of chromate.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromium / analysis
  • Chromium / chemistry*
  • Ferric Compounds / chemistry
  • Iron / chemistry*
  • Kinetics
  • Oxidation-Reduction
  • Plant Extracts / chemistry
  • Polyphenols / chemistry*
  • Water Pollutants, Chemical / analysis
  • Water Pollutants, Chemical / chemistry*
  • Water Purification / methods*

Substances

  • Ferric Compounds
  • Plant Extracts
  • Polyphenols
  • Water Pollutants, Chemical
  • Chromium
  • chromium hexavalent ion
  • Iron