Decolorization of Reactive Black 5 and Reactive Red 198 using Nanoscale Zerovalent Iron
Residual dye contents in textile dyeing wastewater have complex aromatic structures that are resistant to degrade in biological wastewater treatment. The objectives of this study were to determine the effectiveness of nanoscale zerovalent iron (NZVI) to decolorize Reactive Black 5 (RB5) and Reactive Red 198 (RR198) in synthesized wastewater and to investigate the effects of the iron particle size, iron dosage and solution pHs on the destruction of RB5 and RR198. Synthesized NZVI was confirmed by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The removal kinetic rates (kobs) of RB5 (0.0109 min-1) and RR198 (0.0111 min-1) by 0.5% NZVI were many times higher than those of microscale zerovalent iron (ZVI) (0.0007 min-1 and 0.0008 min-1, respectively). The iron dosage increment exponentially increased the removal efficiencies of both RB5 and RR198. Additionally, lowering pH from 9 to 5 increased the decolorization kinetic rates of both RB5 and RR198 by NZVI. The destruction of azo bond (N=N) in the chromophore of both reactive dyes led to decolorization of dye solutions.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1060990Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2138
 H. Zollinger, Colour Chemistry-Synthesis, Properties and Application of Organic Dyes and Pigments, VCH, NewYork, 1987.
 N. Dizge, C. Aydiner, E. Demirbas, M. Kobya, and S. Kara, "Adsorption of reactive dyes from aqueous solutions by fly ash: Kinetic and equilibrium studies," Journal of Hazardous Materials, vol. 150, pp. 737-746, 2008.
 Y-P Sun, X. Li, J. Cao, W. Zhang and H. P. Wang, "Characterization of zero-valent iron nanoparticles," Advances in Colloid and Interface Science, vol. 120, pp. 47-56, 2006.
 H. L. Lien and W. Zhang, "Nanoscale iron particles for complete reduction of chlorinated ethenes," Colloids and Surfaces A: Physicochemical and Engineering Aspects, vol. 191, pp. 97-105, 2001
 W. Zhang, "Nanoscale iron particles for environmental remediation: an overview," Journal of Nanoparticle Research, vol. 5, pp. 323-332, 2003.
 C. Wang and W. Zhang, "Nanoscale metal particles for dechlorination of PCE and PCBs," Environ. Sci. Technol., vol. 31, no. 7, pp. 2154-2156, 1997.
 H-Y Shu, M-C Chang, H-H Yu, and W-H Chen, "Reduction of an azo dye Acid Black 24 solution using synthesized nanoscale zerovalent iron particles," Journal of Colloid and Interface Science, vol. 314, pp. 89-97, 2007.
 C. Huanga, W-P Hsieh, J. R. Pan, and S-M Chang, "Characteristic of an innovative TiO2/Fe0 composite for treatment of azo dye," Separation and Purification Technology, vol.58, no. 1, pp. 152-158, 2007.
 P. Siripannon (2007, August 8). Scientific Intruments Service Centre : SISC, X-Ray Diffractometer (XRD). Available: http://www.kmitl.ac.th/sisc/XRD/GettingStratOf_XRD1.htm
 T. L. Johnson, M. M. Scherer, and P. G. Tratnyek, "Kinetics of halogenated organic compound degradation by iron metal," Environ. Sci. Technol., vol. 30, no. 8, pp. 2634-2640, 1996.
 M.C. Chang, H.Y. Shu, H.H. Yu, Y.C. Sung, "Reductive decolorization and total organic carbon reduction of the diazo dye C.I. Acid Black 24 by zerovalent iron powder," J. Chem. Technol. Biotechnol, vol. 81, pp. 1259-1266, 2006.
 J. Cao, L. Wei, Q. Huang, L. Wang, and S. Han, "Reducing degradation of azo dyes by zero-valent iron in aqueous solution," Chemosphere, vol. 38, no. 3, pp. 565-57, 1999.
 W. Feng, D. Nansheng, and H. Helin, "Degradation mechanism of azo dye C. I. reactive red 2 by iron powder reduction and photooxidation in aqueous solutions," Chemosphere, vol. 41, pp. 233-1238, 2000.
 S. Nam and P. G. Tratnyek, "Reduction of azo dyes with zero-valent iron," Water Research., vol. 34, no. 6, pp. 1837-1845, 2000.
 H. Zhang, L. Duan, Y. Zhang, and F. Wu, "The use of ultrasound to enhance the decolorization of the C.I. Acid Orange 7 by zero-valent iron," Dyes and Pigments, vol. 65, pp. 39-43, 2005.