Kinetics of Fe3O4-CoO/Al2O3 catalytic ozonation of the herbicide 2-(2,4-dichlorophenoxy) propionic acid

作者：Tong, Shao-Ping^*; Shi, Rui; Zhang, Hua; Ma, Chun-an

来源：Journal of Hazardous Materials, 2011, 185(1): 162-167.

DOI：10.1016/j.jhazmat.2010.09.013

• Catalytic ozonation
• Fe3O4-CoO/Al2O3
• 2,4-DP
• Pseudo-first-order
• Kinetics

The presence of Fe3O4-CoO/Al2O3 can improve degradation efficiency significantly during the ozonation of the herbicide 2-(2,4-dichlorophenoxy) propionic acid (2,4-DP). The main factors affecting degradation efficiency, such as pH, the catalyst concentration and addition of the scavenger, were investigated. The kinetics of the catalytic ozonation are also discussed. The results indicate that two factors, the oxidation after adsorption of 2,4-DP and the oxidation of hydroxyl radicals ((OH)-O-center dot), lead to a great enhancement in ozonation efficiency during the catalytic ozonation of 2,4-DP in the presence of Fe3O4-CoO/Al2O3, in which the oxidation of the (OH)-O-center dot plays an important role. Under controlled conditions, the apparent reaction rate constants for the degradation of 2,4-DP were determined to be 2.567 x 10(-4) s(-1) for O-3 and 1.840 x 10(-3) s(-1) for O-3/Fe3O4-CoO/Al2O3. The results from the analysis of the reaction kinetics using the relative method showed that O-3/Fe3O4-CoO/Al2O3 possessed a larger R-ct (R-ct is defined as the ratio of the (OH)-O-center dot exposure to the O-3 exposure, R-ct = integral C-OH(t) dt/ integral C-O3(t) dt) than O-3, indicating that O-3/Fe3O4-CoO/Al2O3 produced more hydroxyl radicals.

• 出版日期2011-1-15
• 单位浙江工业大学