Homogeneous modified Fenton-like oxidation using FeIII-gallic acid complex for ibuprofen degradation at neutral pH

• Published in: Desalination and water treatment Vol. 234; pp. 147 - 157
• Main Authors: Lekikot, B., Mammeri, L., Talbi, K., Benssassi, M.E., Abdessemed, A., Sehili, T.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-09-2021
• Subjects: Chemical oxidation; FeIII-GA complex; Hydroxyl radicals; Ibuprofen; Neutral medium; Hydroxyl radicals; Neutral medium; FeIII-GA complex; Chemical oxidation; Ibuprofen
• ISSN: 1944-3986; 1944-3986
• DOI: 10.5004/dwt.2021.27626

This study aims to find a green method for the degradation of organic pollutants in water treatment. We found that chemical oxidation is an effective process in the treatment of an aqueous solution contaminated by ibuprofen (IBP). To demonstrate the application of the modified Fenton-like process under neutral pH conditions, gallic acid (GA) was used as a complexing agent to solubilize iron in a neutral aqueous solution. Our results show that 90.9% complexation was obtained by FeIII:GA ratio of 1:2 and stability constant of logβ = 11.66 at pH 7. The catalytic activation of the FeIII-GA complex was initiated by the addition of 5 mM of hydrogen peroxide (H2O2) to the neutral medium. The reduction of FeIII was instantaneous and consequently, the degradation of IBP was achieved by the formation of the hydroxyl radicals (•OH) generated during the Fenton-like reaction. All experiments were performed at natural conditions of temperature with an initial IBP concentration of 0.05 and 0.1 mM of FeIII-GA complex at pH 7. The effect of solution pH, temperature, dosage of H2O2, dosage of IBP, and dosage of FeIII-GA complex on the degradation efficiency was also studied. An important degradation was obtained by choosing the initial doses of 5 mM H2O2 and 0.1 mM of the FeIII-GA complex. IBP oxidation rates are found to be directly proportional to the increase of environmental temperature. The total organic carbon experiments showed mineralization of 88.81% of the organic carbon of IBP after 24 h of treatment in the presence of FeIII-GA complex. This work enriches academic knowledge on the feasibility of degrading IBP based on the organic iron complex as a possible green technology.