Toxicity Assessment and Degradation of Disperse Azo Dyes by Photoelectrocatalytic Oxidation on Ti/TiO2 Nanotubular Array Electrodes
-
M. E. Osugi
,
C. R. Chenthamarakshan
Abstract
The feasibility of photobleaching and detoxification of three disperse azo dyes, namely, Disperse Orange 1, Disperse Red 1 and Disperse Red 13, in 0.1 mol L-1 Na2SO4 containing anionic surfactant was investigated using Ti/TiO2 nanotubular array electrodes prepared by the electrochemical anodization of Ti foil. The results were compared with nanoporous Ti/TiO2 electrodes prepared by the sol-gel method. After 60 min of photoelectrocatalytic oxidation of solutions containing 5.0 × 10-5 mol L-1 of Disperse Red 1, Disperse Orange 1 and Disperse Red 13 and 80 mg L-1 of anionic surfactant (Emulsogen) under UV light and an applied potential of +1.0 V (vs. Ag|AgCl|satd. KCl reference electrode), 100% of discoloration was obtained for all the dyes investigated. The rate constants for the nanotubular TiO2 array were almost 2-3 times higher for the photoelectrocatalytic removal of these dyes compared to their sol-gel derived counterparts. Measurement of TOC removal showed ca. 70% reduction after 3 h of photoelectrocatalytic oxidation and the HPLC chromatograms presented complete extinction of the signals. All the samples of dyes extracted in organic phase, without surfactant influence, presented lower toxicity when submitted to photoelectrocatalytic oxidation suggesting that this process would be a good option to remove disperse azo dyes from aqueous media and decrease their cytotoxicity. However it is worth noting that the Emulsogen anionic surfactant presented an increase in the acute toxicity for human embryonic kidney (HEK293) cells even after photoelectrocatalysis and indicates the requirement of other auxiliary procedures before its own release to the aquatic environment. These results underline the need for caution in interpreting toxicity data when a surfactant is also present in addition to an organic dye.
© 2016 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Toxicity Assessment and Degradation of Disperse Azo Dyes by Photoelectrocatalytic Oxidation on Ti/TiO2 Nanotubular Array Electrodes
- Photolysis and TiO2 Photocatalytic Treatment of Naproxen: Degradation, Mineralization, Intermediates and Toxicity
- Oxidation of Higher Alkanes at Moderate Reaction Conditions with Ozone in Presence of Mesoporous Materials
- Modulating the Oxidation of FMNH2 by Organophosphorus Compounds
- Enhancement of the Photodegradation of Methylene Blue by Combined Titania Photocatalyst and Photo-Fenton
- Epoxidation of Allyl Alcohol to Glycidol over Titanium-Silicalite Ti-Beta and Ti-MCM-41 Catalysts
- Photocatalysis with TiO2 and SnO2/TiO2 Films Examined by a Kinetic Model
- Photolytic and Photocatalytic Diminution and Preliminary Genotoxicity Studies of 2-Chloropyridine
- Photocatalytic Degradation of 4-Nitrophenol in a Continuous Reactor Containing Titanium Dioxide Supported on Glass Beads
- Photocatalytic Inactivation of Wild and Hyper-Adherent E. Coli Strains in Presence of Suspended or Supported TiO2. Influence of the Isoelectric Point of the Particle Size and of the Adsorptive Properties of Titania
- Comparison of UV- and UV/VUV-Induced Photolytic and Heterogeneous Photocatalytic Degradation of Phenol, with Particular Emphasis on the Intermediates
- Effect of Ozone Oxidation on the Molecular and Kinetic Properties of Effluent Organic Matter
- Treatment of Antibiotic Formulation Wastewaters by Fenton Process
- Homogeneous and Heterogeneous Catalytic Ozonation of Pulp Bleaching Effluent
- Spectroscopic and Mass-Spectrometric Study of Acridine Orange Photodegradation on the Surface of Mesoporous TiO2, SiO2 /TiO2 and SiO2 Films
- Application of Response Surface Methodology to Optimise C.I. Acid Orange 7 Azo Dye Mineralization by UV/H2O2 Process
- Chemical Treatment by Fenton’s Reagent Oxidation and Ozonation of Wastewaters from Olive Oil Mill
- Analysis of Primary Degradation and Decolourization of Dyes in Water by an H2O2/UV Advanced Oxidation Process
- A Novel Adsorption/Saturation Approach to Ultrasonic Degradation of Phenol
Articles in the same Issue
- Toxicity Assessment and Degradation of Disperse Azo Dyes by Photoelectrocatalytic Oxidation on Ti/TiO2 Nanotubular Array Electrodes
- Photolysis and TiO2 Photocatalytic Treatment of Naproxen: Degradation, Mineralization, Intermediates and Toxicity
- Oxidation of Higher Alkanes at Moderate Reaction Conditions with Ozone in Presence of Mesoporous Materials
- Modulating the Oxidation of FMNH2 by Organophosphorus Compounds
- Enhancement of the Photodegradation of Methylene Blue by Combined Titania Photocatalyst and Photo-Fenton
- Epoxidation of Allyl Alcohol to Glycidol over Titanium-Silicalite Ti-Beta and Ti-MCM-41 Catalysts
- Photocatalysis with TiO2 and SnO2/TiO2 Films Examined by a Kinetic Model
- Photolytic and Photocatalytic Diminution and Preliminary Genotoxicity Studies of 2-Chloropyridine
- Photocatalytic Degradation of 4-Nitrophenol in a Continuous Reactor Containing Titanium Dioxide Supported on Glass Beads
- Photocatalytic Inactivation of Wild and Hyper-Adherent E. Coli Strains in Presence of Suspended or Supported TiO2. Influence of the Isoelectric Point of the Particle Size and of the Adsorptive Properties of Titania
- Comparison of UV- and UV/VUV-Induced Photolytic and Heterogeneous Photocatalytic Degradation of Phenol, with Particular Emphasis on the Intermediates
- Effect of Ozone Oxidation on the Molecular and Kinetic Properties of Effluent Organic Matter
- Treatment of Antibiotic Formulation Wastewaters by Fenton Process
- Homogeneous and Heterogeneous Catalytic Ozonation of Pulp Bleaching Effluent
- Spectroscopic and Mass-Spectrometric Study of Acridine Orange Photodegradation on the Surface of Mesoporous TiO2, SiO2 /TiO2 and SiO2 Films
- Application of Response Surface Methodology to Optimise C.I. Acid Orange 7 Azo Dye Mineralization by UV/H2O2 Process
- Chemical Treatment by Fenton’s Reagent Oxidation and Ozonation of Wastewaters from Olive Oil Mill
- Analysis of Primary Degradation and Decolourization of Dyes in Water by an H2O2/UV Advanced Oxidation Process
- A Novel Adsorption/Saturation Approach to Ultrasonic Degradation of Phenol
