title: Comparison of classical fenton, nitrilotriacetic acid (NTA)-Fenton, UV-Fenton, UV photolysis of Fe-NTA, UV-NTA-Fenton, and UV-H2O2for the degradation of cyclohexanoic acid.
abstract: The treatment of a naphthenic acid model compound, cyclohexanoic acid, with classical Fenton, UV-H2O2, UV-Fenton, nitrilotriacetic acid (NTA)-Fenton, UV-NTA-Fenton, and UV photolysis of Fe-NTA processes at pHs 3 and 8 was investigated. At 1.47 mM H2O2, 0.089 mM Fe, and 0.18 mM NTA, the UV-NTA-Fenton process at pH 3 exhibited the highest H2O2decomposition (100% in 25 min), CHA removal (100% in 12 min) with a rate constant of 0.27 ± 0.025 min-1, and NTA degradation (100% in 6 min). Due to the formation of H2O2-Fe(III)NTA adduct, the total Fe concentration in the UV-NTA-Fenton system (0.063 mM at the end of the reaction) at pH 8 was much higher than that in the UV photolysis of Fe(III)NTA process (0.024 mM). The co-complexing effect of borate buffer helped to keep iron soluble; however, it imposed a negative influence on the CHA degradation in the UV-NTA-Fenton process (68% CHA removal in 60 min in the borate buffer compared to 92% in MilliQ water). The results demonstrated that the most efficient process for the CHA degradation under the experimental conditions was the UV-NTA-Fenton process at pH 3.
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada.
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Klamerth
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada.
authors.forename: Pamela
authors.initials: P
authors.lastname: Chelme-Ayala
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, T6G 1H9, Canada. Electronic address: mgamalel-din@ualberta.ca.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Gamal El-Din
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry / Q000528:radiation effects; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D009571:Nitrilotriacetic Acid / Q000031:analogs & derivatives / Q000737:chemistry*; D010084:Oxidation-Reduction; D010782:Photolysis; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000528:radiation effects; D018508:Water Purification / Q000379:methods
chemical_list: D002264:Carboxylic Acids; D014874:Water Pollutants, Chemical; D006861:Hydrogen Peroxide; D007501:Iron; D009571:Nitrilotriacetic Acid
keywords: Borate buffer; Cyclohexanoic acid; H(2)O(2)-adduct; Nitrilotriacetic acid; UV-Fenton