Kinetics and Mechanism of Humic Acids Degradation by Ozone in the Presence of CeO₂/AC

Abstract

This work investigated the catalytic ozonation of humic acids extracted from landfill leachate in the presence of CeO 2 /AC with focus on the kinetics of humic acids degradation. It was confirmed that the degradation of humic acids mainly took place in the solution bulk. The direct and indirect reaction constants of ozone against humic acids were determined. By analyzing the contributions of direct ozone oxidation and indirect • OH radicals oxidation to humic acids removal, it was found that • OH radicals oxidation predominated at all pH, indicating that the catalytic ozonation of humic acids with CeO 2 /AC involved • OH radicals mechanism.

Removal of Benzoic Acid by Catalytic Ozonation with CeO2 Loaded on N, S Co-Doped Activated Carbon Catalyst

“…It was noted that a similar trend of pH effect was observed in single ozonation and catalytic ozonation with Ce/ACNS. The benzoic acid removal was increased with solution pH due to hydroxyl ions initiating ozone decomposition to generate •OH radicals at an alkaline pH [3,4]. The results implied that the indirect oxidation via •OH radicals was effective for benzoic acid degradation.…”

“…Moreover, the addition of AC improved the degradation efficiency of benzoic acid compared to single ozonation. The enhanced removal efficiency of benzoic acid must be mainly attributed to an increase in the ozone decomposition into •OH radicals [3][4][5]. The introduction of N-containing and S-containing groups enhanced the catalytic performance of AC.…”

“…The characters of AC surface had a great influence on the catalytic performance of AC supported catalyst. On one hand, AC was not only used as a supporting material, but also an ozonation catalyst due to its excellent properties in porous structures and adsorption capacity [3][4][5].…”

Efficient adsorption of Hg (II) ions in water by activated carbon modified with melamine

“…Besides, Hg (II) ions adsorption capacity was improved when amino was introduced into the surface of adsorbent. Actually, nitrogen-containing AC has been developed to remove heavy metals [9] and organic pollutants [10][11][12] from aqueous media. This prompted us to investigate the use of nitrogen-containing carbon materials for the adsorption of Hg (II) ions in water.…”

Adsorption of humic acid from landfill leachate by nitrogen-containing activated carbon

“…Therefore, a process which can effectively remove humic substances may be considered as an effective treatment method for landfill leachate [1]. Treatment approaches, such as activated carbon adsorption [2], Fenton treatment [3], H2O2 oxidation [4] and ozone-based advanced oxidation processes [5][6][7] have been extensively investigated in the treatment of landfill leachate. Activated carbon adsorption is an effective method for treatment of high concentrated, toxic and biorefractory wastewater.…”