Journal of Colloid and Interface Science 313 (2007) 248–253 www.elsevier.com/locate/jcis Electrochemical techniques for the removal of Reactofix Golden Yellow 3 RFN from industrial wastes Rajeev Jain ∗ , Shaily Varshney, Shalini Sikarwar Department of Environmental Chemistry, Jiwaji University, Gwalior 474011, India Received 9 February 2007; accepted 17 April 2007 Available online 5 June 2007 Abstract Electrochemical methods for pollution abatement have been shown to be viable alternatives or complementary to biological treatment in some instances, especially when pollutants are recalcitrant to biological processing. Electrochemical oxidation and reduction have been found successful in decomposing the most resilient compounds, and electrolysis is assigned an important role in the elucidation of the electrode process. Small well-defined cathodic and anodic peak were observed that on controlled-potential electrolysis (CPE) reduced substantially with a considerable decrease in color and absorbance. The rate of decrease of the current and absorbance was found to exhibit a first-order dependence. The COD of the solutions showed a decrease from 1416 to 352 mg/L. No peak could be observed in the voltammograms after CPE, indicating the absence of any electroactive substance left in the solutions. Results show that electrochemical reduction is a superior technology for treatment of dyes, as there is no simultaneous addition of anions, such as sulfate or chloride.  2007 Elsevier Inc. All rights reserved. Keywords: Electrochemical methods; Electrode; Reactofix Golden Yellow 3 RFN; COD 1. Introduction The release of azo dyes into the environment is of great concern, due to coloration of natural waters and toxicity, mu- tagenicity, and carcinogenicity of the dyes and their biotrans- formation products [1–9]. Electrochemical methods for pollu- tion abatement have been shown to be a viable alternative to biological treatments [10–18], especially when pollutants are recalcitrant to biological processing. The potential of electro- chemistry for environmental protection has been reviewed in many articles and monographs [19–22]. Electrochemical oxida- tion and reduction were found to be successful in decomposing the most resilient compounds [23–26], and electroanalysis is as- signed an important role in the identification of the end products of electrolysis. The present work reports the results of electro- chemical studies on an azo dye, Reactofix Golden Yellow 3 RFN (Fig. 1), with particular reference to color removal and * Corresponding author. E-mail address: rajeevjain54@yahoo.co.in (R. Jain). wastewater treatment. It is an acid dye and the acidic group acts as an auxochrome in this dye. The electrochemical treatment of textile wastewater has been previously studied in the literature [27–35]. In recent studies, Shen et al. [28] investigated the effect of operational parameters of electrolyte concentration, temperature, stirring, and voltage in the degradation effect of electrochemical treatment of dye wastewater using nanophase TiO 2 catalyst and Co–Bi–PbO 2 /Ti anodes with Na 2 SO 4 electrolyte at applied potential 8 V and temperature 25 ◦ C, except testing their influence. Daneshvar et al. used electrocoagulation for the removal of color from C.I. Basic Red 46 (BR46) and C.I. Basic Blue 3 (BB3) con- taining solutions with NaCl electrolyte [29]. Awad and Galwa studied the electrocatalytic degradation of Acid Blue and Basic Brown dyes from simulated wastewater on a lead dioxide anode in H 2 SO 4 , NaOH, and NaCl electrolytes within a current den- sity range of 0–45 mA/cm 2 [30]. Carneiro et al. investigated the electrochemical oxidation of Reactive Blue 4 using a glassy carbon electrode, reticulated vitreous carbon electrode, and di- mensionally stable anodes of Ti/SnO 2 /SbO 2 /RuO 2 [31]. Sakalis et al. studied the electrolytic degradation of Reactive Orange 91, Reactive Red 184, Reactive Blue 182, and Reactive Black 0021-9797/$ – see front matter  2007 Elsevier Inc. All rights reserved. doi:10.1016/j.jcis.2007.04.035