A computational study of the effect of lamp arrangements on the performance of ultraviolet water disinfection reactors

Xu, Chao; Rangaiah, Gade Pandu; Xin, Zhao

doi:10.1016/j.ces.2014.09.041

Cited by 39 publications

(14 citation statements)

References 21 publications

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“…Modeling by Hofmann and Lawryshyn (2015) found that the reduction equivalent dose from UV reactors in series is additive when there is complete interbank mixing, is more than additive when there is negative correlation between the dose paths in the two reactors, and is less than additive when the correlation is positive. CFD modeling showed that water flow rate and lamp arrangement have complex effects on reactor performance, with parallel lamps performing better than perpendicular lamps (Xu, Rangaiah, and Zhao, 2015). The number of segments needed to discretize UV lamps for fluence rate modeling and dose calculations was optimized using multiple point summation with no reflection and refraction, and reduced the time needed for modeling (Powell and Lawryshyn, 2015).…”

Section: Ultraviolet (Uv) Radiationmentioning

confidence: 99%

Disinfection Processes

Munakata

Kuo²

2016

Water Environment Research

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Section: Ultraviolet (Uv) Radiationmentioning

confidence: 99%

Disinfection Processes

Munakata

Kuo²

2016

Water Environment Research

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“…In this work, several practical factors relating to UV lamps positionings are delineated that results in the variability of UV radiation doses in UV reactors. Xu et al (2015) compared various four-lamp positions in water disinfection UV reactor and discovered that increasing the number of lamps did not improve the UV reactor performance. Additionally, similar findings are stated in the literature (Li et al 2019).…”

Section: Introductionmentioning

confidence: 99%

Computational analysis of three lamp close conduit water disinfection UV reactor

Sultan

Ahmad

Hayat

et al. 2021

Int. J. Environ. Sci. Technol.

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The purpose of ultraviolet (UV) disinfection is to bring to end the growth and procreation of microorganism. UV reactors are used for the UV disinfection of the drinking water. Our goal of the current research work was properly locating the positions of the UV lamps in a three-lamp close conduit water disinfection UV reactor. Three positions of UV lamps are based on vertices of the four basic types of triangles (Equilateral, Right angle, Scalene and Isosceles). The objective function for optimized lamp positioning was Reduction Equivalent Dose (RED). To ascertain efficient UV dose delivery to pathogen, water disinfection UV reactors was simulated with the aid of computational fluid dynamics. The computational investigation was achieved employing ANSYS ® Fluent 15.0 academic version. The turbulent flow was modeled using standard k−ε model, fluence rate (FR) was modeled using UVCalc3D model and pathogen transport was modeled using discrete phase model. The scalene lamp positioning results in highest RED value and isosceles lamp positioning results in lowest RED value. There is meager difference between the RED values of equilateral and scalene lamp positioning. Moreover, we found two lamps on the upstream side and one lamp on the downstream side results in better UV disinfection. The proposed methodology for the three-lamp model provides useful insights to the design and optimization of close conduit water disinfection UV reactor. This research work has evaluated, for the first time, a systematic methodology for three-lamp positioning to ameliorate the performance of UV reactor and has revitalized the comprehension about the contribution of FR distribution within the UV reactor. KeywordsCFD • Fluence rate • Reactor design • Turbulence modeling • UV lamp • Water disinfection List of symbols A and B Constants in logarithm microbial inactivation rate function dt Pathogens residing time (s) I Irradiance of UV radiation (W m −2 ) k Inactivation rate constant (m 2 J −1 ) K in Turbulent kinetic energy (m 2 s −2 ) N Pathogen influent ( −) N 0 Pathogens effluent ( −) N/N 0 Log inactivation ( −) p Means pressure ( −) t Time (s) u i and u j Velocity components (m s −1 ) u in Velocity at inlet (m s −1 ) u i u j Reynolds stress tensor (m 2 s −2 ) ij Kronecker delta function ε in Turbulent dissipation at inlet (m 2 s −3 ) Laminar kinematic viscosity (m 2 s −1 ) t Turbulent kinematic viscosity (m 2 s −1 ) Density (kg m −3 ) k Prandtl-Schmidt number for K in ( −) Prandtl-Schmidt number for K (−) Subscripts i, j Position of a cell in Inlet Abbreviations CFD Computational fluid dynamics DBPs Disinfection-by-products DPM Discrete phase model FR Fluence rate RED Reduction equivalent dose SURF Simultaneous UV FR and fluid dynamics Editorial responsibility: Samareh Mirkia.

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“…The simulation of UV disinfection in an open channel configuration [27] was performed using a combination of four mathematical models (hydrodynamic pattern, intensity field, dose distribution, and inactivation kinetics) fed with several experimental data sets (collimated beam, Doppler laser velocimetry, UV transmittance, and UV output power). The design of the UV reactor (including the water inlet/outlet) and the position and distribution of the UV lamps located inside the reactor modify the fluid pattern and can be described by CFD [28,29]. Therefore, the UV dose within a reactor depends largely on the accuracy to numerically describe the turbulent structures developed based on the geometry of the UV reactor [30][31][32][33].…”

Section: Introductionmentioning

confidence: 99%

E. coli Inactivation Kinetics Modeling in a Taylor-Couette UV Disinfection Reactor

Palacios-Contreras

Sierra

Juárez³

et al. 2020

International Journal of Photoenergy

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A simple model was developed to predict the survival behavior of E. coli subjected to UV disinfection in a Taylor-Couette reactor. The model includes the CFD evaluation of the counterrotating toroidal vortices developed within the annular space of two coaxial cylinders. The UV lamp was located within the diameter of the internal rotating cylinder. The residence time of the bacteria near the UV lamp is, therefore, a function of both the size of the vortex and its angular velocity. The effect of angular velocity on the formation of counterrotating toroidal vortices and their impact on the kinetics of UV microbial inactivation was experimentally evaluated. The kinetics of microbial inactivation follow an apparent first-order kinetic equation between 300 and 2000 revolutions per minute. Therefore, in this range of angular velocities, a set of k values (indirectly taking into account the hydrodynamic pattern and UV irradiance) was obtained for a given concentration of bacteria. Then, the set of k values was correlated with the range of angular velocities applied using the polynomial equation. A k value can be obtained for an unknown angular velocity through the polynomial equation. Therefore, a simulation curve of microbial inactivation can be obtained from the first-order kinetic equation. The efficiency of bacteria removal improves depending on the angular velocity applied. A good agreement is observed between the simulation of the survival behavior of the microorganisms subjected to UV disinfection with the experimental data.

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A computational study of the effect of lamp arrangements on the performance of ultraviolet water disinfection reactors

Cited by 39 publications

References 21 publications

Disinfection Processes

Disinfection Processes

Computational analysis of three lamp close conduit water disinfection UV reactor

E. coli Inactivation Kinetics Modeling in a Taylor-Couette UV Disinfection Reactor

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