Chemical decolorization of the azo dye CI Reactive Orange 96 by various organic/inorganic compounds

✍ Scribed by Eui S Yoo

• Publisher: Wiley (John Wiley & Sons)
• Year: 2002
• Tongue: English
• Weight: 107 KB
• Volume: 77
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/jctb.603

✦ Synopsis

Abstract

Batch experiments were performed to investigate the possibility and kinetics of chemical decolorization of the reactive mono‐azo dye CI Reactive Orange 96 (RO 96) with various compounds such as cysteine, ascorbate, Ti(III)‐citrate, Fe(II)‐sulfate, and yeast extract. Cysteine and ascorbate (10 mmol dm^−3^ respectively) decolorized RO 96 (0.19 mmol dm^−3^) in the absence of oxygen. Increasing the concentration of either reductant (to 20 or 38 mmol dm^−3^) enhanced the decolorization rate, showing first‐order kinetics with respect to both the concentration of the dye and of cysteine or ascorbate. The rate constants, k, for cysteine and ascorbate were 0.0003 and 0.0010 dm^3^mmol^−1^ h^−1^ respectively at pH 7.1 and 33 °C. Ti(III)‐citrate (10 mmol dm^−3^) decolorized RO 96 (0.20 mmol dm^−3^) within 5 min, independent of the presence of oxygen. Fe(II)‐sulfate was not effective in the decolorization of RO 96 at pH 8, whereas a rapid decolorization occurred at pH 12. This study suggests that a variety of abiotic processes may be involved in decolorization under anaerobic conditions.

© 2002 Society of Chemical Industry