119th General Meeting of the KCS

Type Poster Presentation
Area 환경에너지
Room No. 포스터발표장
Time 4월 20일 (목요일) 11:00~12:30
Code ENVR.P-489
Subject Fenton-like reaction of metal ferrite with chelating agents: Batch and feasibility test
Authors 강유경, 장윤석*
POSTECH 환경공학부, Korea
Abstract It has been noticed that some chelating agents can enhance heterogeneous Fenton reactions, as well as homogeneous Fenton reactions. However, the mechanism of the enhanced heterogeneous Fenton reactions remains unclear, due to the ambiguous coexistence of homogeneous and heterogeneous reactions. In the present work, ethylene diamine tetraacetic acid (EDTA) was introduced to study the role of the chelating agent in the oxidation of 4-chlorophenol (4CP) in metal ferrite system. Ferrite has similar structure with magnetite (Fe3O4), which Fe2+ sites were substituted to other metal cations. The presence of some metals in the ferrite structure strongly increased the rate of H2O2 decomposition and the oxidation of the organic molecules. 5 kinds of ferrites were synthesized by co-precipitation method with manganese, cobalt, nickel, copper and zinc. The addition of EDTA in solution accelerated 4CP removal due to the induced homogeneous Fenton reaction by enhanced dissolution of metal cation, and reaction rate was like that (Cu=Ni>Mn>Zn>Co). Meanwhile, the adsorbed EDTA on the catalyst could also enhance 4CP removal. Effects of EDTA surface loadings, chelating agents (EDDS, NTA, oxalic acid and citric acid), initial H2O2 concentrations, initial 4CP concentrations, and initial pH on the reaction kinetics in EDTA modified ferrite/H2O2 system were investigated. Results showed that the surface complexed EDTA (Me2+/Fe3+-EDTA) inhibited H2O2 decomposition by competition for surface active sites. The enhanced 4CP removal by Me2+/Fe3+-EDTA was probably due to the efficient use of reactive oxygen species (ROS). Additionally, field applicability was tested in soil slurry condition using subsurface soil mixed with 4CP spiked solution.
E-mail ygkang74@postech.ac.kr