title: Experimental Assessment of Photon Fluence Rate Distributions in a Medium-Pressure UV Photoreactor.
abstract: The performance of a medium-pressure (MP) mercury lamp photoreactor is strongly influenced by the spatial photon fluence rate (PFR) distributions which are wavelength-dependent. To address this issue, PFR distributions in an MP lamp photoreactor were measured using a 360-degree response microfluorescent silica detector (MFSD). To accurately express the optical behavior in an MP photoreactor, PFR, MFSD response PFR (PFRMFSD), and effective germicidal PFR (PFRGER) were defined and compared. The measured axial and radial PFRMFSDvalues agreed well with the corresponding results from a simulation model (UVCalc). The PFR and PFRGERwere obtained from the measured PFRMFSDby using correction factors calculated by the UVCalc. Under identical UV transmittance (254 nm) conditions (75% and 85%), the weighted average PFRGERvalues were 13.3-18.7% lower than the corresponding PFR values, indicating that PFRGER, rather than PFR should be used in MP photoreactor design to meet disinfection standards. Based on measured lamp output, medium absorption spectrum, MFSD response, and microbial DNA response spectrum, the detailed relationships between the PFR, PFRMFSD, and PFRGERwere elucidated. This work proposes a new method for the accurate description of wavelength-dependent PFR distributions in MP photoreactors, thus providing an important tool for the optimal design of these systems.
authors.affiliation: Lyles School of Civil Engineering, Purdue University , West Lafayette, Indiana 47907, United States.|Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences , 18 Shuang-qing Road, Beijing 100085, China.
authors.forename: Mengkai
authors.initials: M
authors.lastname: Li
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences , 18 Shuang-qing Road, Beijing 100085, China.
authors.forename: Zhimin
authors.identifier: 0000-0002-6555-3381
authors.initials: Z
authors.lastname: Qiang
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences , 18 Shuang-qing Road, Beijing 100085, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Civil and Environmental Engineering, University of Alberta , Edmonton, AB T6G 2W2, Canada.
authors.forename: James R
authors.initials: JR
authors.lastname: Bolton
authors.affiliation: Lyles School of Civil Engineering, Purdue University , West Lafayette, Indiana 47907, United States.|Division of Environmental & Ecological Engineering, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Ernest R
authors.identifier: 0000-0002-4561-8635
authors.initials: ER
authors.lastname: Blatchley
mesh_terms: D004203:Disinfection; D017785:Photons; D011312:Pressure; D014466:Ultraviolet Rays; D018508:Water Purification