Efficient degradation of fulvic acids in water by catalytic ozonation with CeO₂/AC

Abstract

BACKGROUND: Fulvic acids (FA), the main organic compounds in landfill leachate, are toxic and bio-resistant organic compounds. Ozonation is effective in removing non-biodegradable components and the addition of catalysts can improve the removal rates. The objective of this study is to prepare and improve CeO 2 /AC catalyst for catalytic ozonation of FA. RESULTS: The cerium precursor, calcination atmosphere and calcination temperature changed the percentage of Ce 3+ on the surface, thus affecting the catalytic performance of CeO 2 /AC catalyst. A linear relationship was established between the correcting apparent rate constant of FA degradation (k app /S BET ) and the percentage of Ce 3+ on the surface. The CeO 2 /AC with 5% of Ce loading and calcined under hydrogen atmosphere at 450 • C showed the highest catalytic activity, allowing a FA removal efficiency of 83%. The FA removal efficiency and ozone utilization efficiency were enhanced in O 3 /CeO 2 /AC compared with ozonation alone. CONCLUSION: Ce 3+ on the CeO 2 /AC surface is the active site for ozonation, indicating a feasible way to improve the catalytic performance of CeO 2 /AC. The O 3 /CeO 2 /AC process may be applied as a promising treatment method for landfill leachate.

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

“…The presence of the Ce 3+ /Ce 4+ redox couple on the surface of the catalysts was evidenced by XPS analysis. The complete characterization of this material is reported elsewhere (Qin et al 2014). All other chemicals required in the experiments were analytical grade reagents.…”

“…In our previous work (Qin et al 2014), it was found that CeO 2 /AC could obviously promote commercial fulvic acids (FA) degradation at acidic pH and an increase in the catalytic activity with the increase of the percentage of Ce 3+ on the surface was observed. In addition, experiments carried out in the presence of the radical scavenger tert-butanol supported the involvement of • OH radicals in the oxidation mechanism.…”

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.…”