Abatement of the Inhibitory Effect of Chloride Anions on the Photo-Fenton Process

• Published in: Environmental science & technology Vol. 41; no. 24; pp. 8459 - 8463
• Main Authors: Machulek, Amilcar, Moraes, José E. F, Vautier-Giongo, Carolina, Silverio, Cristina A, Friedrich, Leidi C, Nascimento, Cláudio A. O, Gonzalez, Monica C, Quina, Frank H
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.12.2007
• Subjects: Anions; Applied sciences; Biodegradation; Catalysis; Chemical compounds; Chemical reactions; Chloride; Chlorides; Chlorides - chemistry; Exact sciences and technology; Gasoline; Hydrogen-Ion Concentration; Ions; Kinetics; Organic chemicals; Phenols; Photochemicals; Photochemistry; Pollution; Q1; Remediation and Control Technologies; Wastewater; Hydrogen peroxide; Pollutant behavior; Pollution control; Waste water; Ultraviolet radiation; Chlorides; Phenols; Fenton reaction; Oxidation; Pollution abatement; Kinetics; Photooxidation; Photochemical degradation
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es071884q

The inhibition of the photo-Fenton (Fe2+/Fe3+, H2O2, UV light) degradation of synthetic phenol wastewater solutions by chloride ions is shown to affect primarily the photochemical step of the process, having only a slight effect on the thermal or Fenton step. Kinetic studies of the reactions of oxoiron (IV) (FeO2+) with phenol indicate that, if FeO2+ is formed in the photo-Fenton degradation, its role is probably minor. Finally, it is shown that, for both a synthetic phenol wastewater and an aqueous extract of Brazilian gasoline, the inhibition of the photo-Fenton degradation of the organic material in the presence of chloride ion can be circumvented by maintaining the pH of the medium at or slightly above 3 throughout the process, even in the presence of significant amounts of added chloride ion (0.5 M).