Assessment of Polyphenol Coated Nano Zero Valent Iron for Hexavalent Chromium Removal from Contaminated Waters

• Published in: Bulletin of environmental contamination and toxicology 2015-03, Vol.94 (3), p.302-307
• Main Authors: Mystrioti, C., Sparis, D., Papasiopi, N., Xenidis, A., Dermatas, D., Chrysochoou, M.
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Assessments; Bioremediation; Camellia sinensis; Chromates; Chromium; Chromium - analysis; Chromium - chemistry; Contamination; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Eugenia; Ferric Compounds - chemistry; Green tea; Hexavalent chromium; Iron; Iron - chemistry; Kinetics; Mentha spicata; Nanoparticles; Nanostructure; Oxidation-Reduction; Plant extracts; Plant Extracts - chemistry; Pollution; Polyphenols; Polyphenols - chemistry; Pomegranates; Punica granatum; Raw materials; Reduction; Soil Science & Conservation; Syzygium aromaticum; Waste Water Technology; Water Management; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - chemistry; Water pollution; Water Pollution Control; Water Purification - methods
• ISSN: 0007-4861; 1432-0800
• DOI: 10.1007/s00128-014-1442-z

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.