title: Degradation mechanism of Methyl Orange by electrochemical process on RuO(x)-PdO/Ti electrode.
abstract: The electrochemical degradation of Methyl Orange in 0.1 M NaCl solution over RuO(x)-PdO/Ti anode was investigated. Chemical oxygen demand (COD), ion chromatography (IC), Fourier Transform Infrared Spectroscopy (FTIR) and Gas chromatography-mass spectrometry (GC-MS) were employed to detect the intermediates formed during the electrochemical degradation. In the present reaction system, Methyl Orange could be effectively degraded. After 1 h treatment, the discoloration could reach 97.9% with COD removal of 57.6%. The results indicated that in the presence of chloride, the electrolysis was able to oxidise the dye with partial mineralisation of carbon, nitrogen and sulfur into CO(2), NO(-)(3) and SO(2-)(4), respectively. After 8 h electrolysis, 62% of sulfur contained in Methyl Orange was transformed to SO(4)(2-), and 17.6% of nitrogen changed to NO(3)(-). The intermediates during electroprocess were detected to be low molecular weight compounds, chlorinated compounds, derivatives of benzene and long chain alkanes. Based on these data, a possible degradation mechanism of Methyl Orange was proposed.
authors.affiliation: College of Chemistry, Sichuan University, Chengdu, China. dulin112233@yahoo.com.cn
authors.forename: Lin
authors.initials: L
authors.lastname: Du
authors.forename: Jin
authors.initials: J
authors.lastname: Wu
authors.forename: Song
authors.initials: S
authors.lastname: Qin
authors.forename: Changwei
authors.initials: C
authors.lastname: Hu
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D002852:Chromatography, Ion Exchange; D004396:Coloring Agents / Q000737:chemistry; D004566:Electrodes; D004572:Electrolysis; D008401:Gas Chromatography-Mass Spectrometry; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry; D017975:Ruthenium Compounds / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014025:Titanium / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D017975:Ruthenium Compounds; D014874:Water Pollutants, Chemical; D010165:Palladium; C100258:methyl orange; C048320:palladium oxide; D014025:Titanium