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Indexed by:期刊论文

Date of Publication:2018-08-07

Journal:ENVIRONMENTAL SCIENCE & TECHNOLOGY

Included Journals:PubMed、SCIE

Volume:52

Issue:15

Page Number:8701-8711

ISSN No.:0013-936X

Abstract:Reactor design is significant to catalytic ozonation for an efficient mass transfer and exposure of the powerful but short-lived hydroxyl radicals (HO center dot). Herein, five groups of zinc oxide nanotube arrays with pore sizes from 168 to 10 nm were produced as mini-column catalyst reactors (MCRs) for internal catalytic ozonation, whose performance was comparatively studied on the kinetics of ozone transfer, consumption, and radical probe interaction. Using an R-CT value describing HO center dot exposure, all the MCRs with sufficient ozone transfer featured an R-CT level of at least 3.2 X 10(-6), which is substantially higher than most values in referenced works (10(-9)similar to 10(-6)) and that for microscale reactors in our work (similar to 10(-5)). Furthermore, the HO center dot exposure dramatically increased with diminishing pore size, causing an elevated R-CT up to 8.0 X 10(-5) for the smallest MCR with 10 nm pore. The interphase formed in this flow-through system might have enriched HO center dot radicals produced via surface, and for a smaller MCR, the effect would be greater with a more confined microfluidic region. Investigations on electron paramagnetic resonance and the treatment of ozone-recalcitrant organics corroborated the nanoscale effect of MCR on augmentation of HO center dot exposure. This study offers a new way to design nanotube reactors for internal HO center dot-based heterogeneous catalysis