title: Decolorization of azo dyes Orange G using hydrodynamic cavitation coupled with heterogeneous Fenton process.
abstract: The present work demonstrates the application of the combination of hydrodynamic cavitation (HC) and the heterogeneous Fenton process (HF, Fe(0)/H2O2) for the decolorization of azo dye Orange G (OG). The effects of main affecting operation conditions such as the inlet fluid pressure, initial concentration of OG, H2O2 and zero valent iron (ZVI), the fixed position of ZVI, and medium pH on decolorization efficiency were discussed with guidelines for selection of optimum parameters. The results revealed that the acidic conditions are preferred for OG decolorizaiton. The decolorization rate increased with increasing H2O2 and ZVI concentration and decreased with increasing OG initial concentration. Besides, the decolorization rate was strongly dependent on the fixed position of ZVI. The analysis results of degradation products using liquid chromatography-ESI-TOF mass spectrometry revealed that the degradation mechanism of OG proceeds mainly via reductive cleavage of the azo linkage due to the attack of hydroxyl radical. The present work has conclusively established that the combination of HC and HF can be more energy efficient and gives higher decolorization rate of OG as compared with HC and HF alone.
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310035, China.
authors.forename: Meiqiang
authors.initials: M
authors.lastname: Cai
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310035, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Su
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310035, China.
authors.forename: Yizu
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310035, China.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Wei
authors.affiliation: Zhejiang Provincial Key Laboratory of Health Risk Appraisal for Trace Toxic Chemicals, Ningbo Municipal Center for Disease Control and Prevention, Ningbo 315010, China; Ningbo Key Laboratory of Poison Research and Control, Ningbo Municipal Center for Disease Control and Prevention, Ningbo 315010, China. Electronic address: jmcjc@163.com.
authors.forename: Micong
authors.initials: M
authors.lastname: Jin
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310035, China.
authors.forename: Haojie
authors.initials: H
authors.lastname: Zhang
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310035, China. Electronic address: dcy0915@126.com.
authors.forename: Chunying
authors.initials: C
authors.lastname: Dong
authors.affiliation: Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, OH 43210, United States.
authors.forename: Zongsu
authors.initials: Z
authors.lastname: Wei
keywords: Decolorization; Fenton process; Hydrodynamic cavitation; Orange G; Zero-valent iron