Ultraviolet Reactor Research Articles

Performance assessment, through numerical simulation and experimental evaluation, of a thin-film ultraviolet reactor for the processing of fruit juices

Abstract The paper presents a numerical approach to investigate the performance of a thin-film ultraviolet reactor in treating three different fruit juices (apple, orange and pineapple) with UV-C radiation, under six flow rate conditions. Minimum, average and maximum doses were calculated for each configuration, by integrating, over time the irradiance over one thousand different streamlines. The presented approach allows for calculating the dose distribution achieved, thus assessing both the fulfilment of regulatory requirements and the uniformity of the treatment. Experimental tests were finally performed on both apple and orange juice, with a flow rate of 80 L/h. For apple juice, more than 3 Log CFU/mL reductions were obtained on Escherichia coli ATCC 11,229, while, for orange juice, a negligible reduction (0.05 Log CFU/mL) was achieved. These results, according to biodosimetry data from other studies, correspond to UV-C dose distributions that confirm those calculated.

Monitoring and evaluation of a compact system for gray water treatment and agricultural use

Water reuse is necessary for industrial, commercial and domestic activities, being a reality in several countries, but not yet widespread in Brazil, an efficient instrument for managing water resources and minimizing water scarcity in the semi-arid region. The aim is to monitor a compact gray water treatment and agricultural use station, consisting of a septic tank, anaerobic filter and artificial ultraviolet reactor, which was installed in an experimental area of the Universidade Federal Rural do Semi-Árido, Mossoró/RN. From October to December 2017, the system's treatment performance was evaluated through physical-chemical analyses: Biochemical Oxygen Demand, Chemical Oxygen Demand, pH, electrical conductivity and turbidity, microbiological: Total coliforms and Escherichia coli of gray water with and without treatment, in order to meet the standards established for water reuse for agricultural and forestry purposes. The results indicated that the system showed efficiency in removing the studied variables and, consequently, meeting the maximum permissible standards, with the exception of turbidity and Escherichia coli.

Performance of Reynolds Averaged Navier–Stokes and Large Eddy Simulation Models in Simulating Flows in a Crossflow Ultraviolet Reactor: An Experimental Evaluation

Performance of Reynolds Averaged Navier–Stokes and Large Eddy Simulation Models in Simulating Flows in a Crossflow Ultraviolet Reactor: An Experimental Evaluation

Dose Distribution Scaling and Validation of Ultraviolet Photoreactors Using Dimensional Analysis.

Ultraviolet (UV) disinfection is commonly applied in the treatment of drinking water and wastewater. The performance of UV disinfection systems is governed by the UV dose distribution delivered to the fluid, which is an intrinsic characteristic of the reactor under a given operating condition. Current design and validation approaches are based on empirical methods that are expensive to apply and provide limited information about the UV photoreactor behavior. To address this issue, a dose distribution scaling method was developed based on dimensional analysis (i.e., application of the Buckingham-π theorem). Three dimensionless groups representing UV dose, reactor geometry, and UV absorption behavior were defined. Using these groups, the approach was applied for the analysis of 15 operating conditions, defined by process variables of volumetric flow rate, UV transmittance, and lamp power. The approach was demonstrated to allow scaling of the dose distribution with these critical, dimensionless variables and yielded close agreement between predictions of disinfection efficacy against MS2 and E. coli based on the scaling approach with conventional CFD-E' modeling results. The approach thus provides a low-cost, rapid method for predicting the performance of UV disinfection systems across a wide range of operating conditions and against essentially any microbial challenge agent.

Drastic Microbial Count Reduction in Soy Milk Using Continuous Short-Wave Ultraviolet Treatments in a Tubular Annular Thin Film UV-C Reactor.

Vegetative cells of Listeria monocytogenes and Escherichia coli and spores of Bacillus subtilis and Aspergillus niger were inoculated in soy milk at an initial concentration of ≈5 log CFU/mL. Inoculated and control (non-inoculated) soy milk samples were submitted to three types of treatments using a tubular annular thin film short-wave ultraviolet (UV-C) reactor with 1 mm of layer thickness. Treatments applied depended on the flow rate and the number of entries to the reactor, with UV-C doses ranging from 20 to 160 J/mL. The number of entries into the reactor tube (NET) was established as the most determining parameter for the efficiency of the UV-C treatments. Conidiospores of A. niger were reported as the most resistant, followed by B. subtilis spores, while vegetative cells were the most sensible to UV-C, with Listeria monocytogenes being more sensible than Escherichia coli. Treatments of just 80 J/mL were needed to achieve a 5 log CFU/mL reduction of L. monocytogenes while 160 J/mL was necessary to achieve a similar reduction for A. niger spores.

Experiment on the formaldehyde removal performance of TiO2 coating agent for finishing materials

As the frequency of indoor habitation escalates and advancements in building technology optimize airtightness, the importance of maintaining high-quality indoor air has grown increasingly critical. This urgency is further amplified by the proliferation of chemical building materials, necessitating more effective strategies for air pollutant abatement. To address this need, the current study explored the utility of titanium dioxide photocatalysts, which possess chemical decomposition capabilities, as a means of improving air quality within indoor environments. To verify the effectiveness of this approach, the research focused on the removal of formaldehyde—a quintessential indoor air pollutant—by incorporating a titanium dioxide photocatalyst into a coating agent commonly employed in construction materials. Notably, ultraviolet (UV) light, essential for activating the photocatalytic process, is generally absent in indoor settings. To mitigate this limitation, a consistent source of UV radiation was provided through the use of an UV lamp. Adhering to protocols outlined by the International Organization for Standardization, we employed a photoreactor to evaluate the photocatalytic efficiency of the composite material under varying intensities of UV radiation and reactor volumes. The results unequivocally confirmed that variations in UV radiation intensity and reactor volume significantly influenced the photocatalytic effectiveness of the material, resulting in a demonstrable reduction in pollutant concentrations. These findings suggest the feasibility of utilizing titanium dioxide photocatalysts for mitigating outdoor air pollutants, where natural UV radiation is more readily available. However, for indoor applications, the absence of naturally occurring UV radiation presents a considerable challenge. Overcoming this constraint could facilitate the indoor application of photocatalytic coatings, as informed by the optimal conditions of low pollutant reactivity and robust UV radiation revealed in this study, thereby substantially enhancing indoor air quality.

Radiation Modeling and the Simulation of the Microorganism Disinfection in Ultraviolet Reactors

Ultraviolet disinfection can effectively destroy waterborne microorganisms. Modeling ultraviolet disinfection includes the solution of the flow field, the radiation field, and the concentration field. Radiation plays an important role in the inactivation kinetics of microorganisms. The present study presents the irradiance method to determine the irradiation flux at the lamp surface, which satisfies the energy conservation law. A careful analysis shows that the fluence rate method may overestimate the emitted energy of the lamp nearly 30–40% and violates the energy conservation law. The simulation of ultraviolet reactors shows that the fluence rate is overestimated by the fluence rate method. The concentration of microorganisms in ultraviolet reactors is also overestimated nearly 32% by the fluence rate method than by the irradiance method. The LOG reduction predicted using the fluence rate method is nearly 50% more than that using the irradiance method. The present irradiance method can ensure energy conservation and predict the correct disinfection performance in ultraviolet reactors.

Inactivation efficacy and reactivation of fecal bacteria with a flow-through LED ultraviolet reactor: Intraspecific response prevails over interspecific differences

Treatment with ultraviolet (UV) light is a common option for inactivating waterborne organisms. The mercury vapor lamps conventionally used as a source of UV-C light for water disinfection are eventually replaced by light emitter diodes (LEDs) in the middle term due to their higher efficiency and lack of hazardous materials. Nonetheless, biological mechanisms for repairing UV damage caused by the UV treatment are some of its significant undesirable features. The objective of this study is to evaluate and compare the UV-resistance and the reactivation degree in different strains of E. coli and E. faecalis treated with a flow-through reactor equipped with LEDs with an emission range between 265 and 285 nm. The treated organisms were subjected to various illumination regimes after the UV irradiation. The results obtained indicated that intraspecific differences between the strains of E. coli were greater than the interspecific differences with respect to E. faecalis in terms of UV-resistance and repairing potential. The UV doses necessary to achieve four log-reductions ranged from 10.2 to 16.3 mJ cm−2 for E. coli and from 11.1 to 11.4 for mJ cm−2 for E. faecalis. Dark repair was not observed within 24 h after the UV irradiation whereas the degree of photorepair depended on both the bacteria strain and the applied UV dose. The exposure of the irradiated organisms to an illuminated environment entailed and increasing between the 18 % and the 160 % of the UV dose required to achieve four log-reductions.

Planar reactor with a serpentine channel for water disinfection by using ultraviolet C light-emitting diodes

Water sterilization efficiency is affected by water flow patterns and irradiance distribution, which in turn are affected by reactor design. In this study, a planar flow reactor with a serpentine channel was used to treat drinking water by using 278-nm ultraviolet (UV)-C light-emitting diodes. The effects of various water flow rates, channel widths, and baffle lengths were investigated to understand their effects on fluid mixing and flow trajectory. The experimental results revealed that the UV reactor with a channel width of 13 mm exhibited the highest log inactivation value for Escherichia coli among the reactors with three different channel widths. This is because this width maximized the exposure time and increased the secondary flow at the turn regions in the serpentine channel. Furthermore, the baffle length dramatically affected the flow trajectory, circulation zones, and microbial exposure time. This length was optimized at 22 mm for all the investigated flow rates. The developed UV reactor achieved an inactivation value of 4.0 log for E. coli at a maximum water flow rate of 80 mL/min.

A novel UV-LED hydrogen peroxide electrochemical photoreactor for point-of-use organic contaminant degradation

The degradation of organic contaminants is typically achieved by exposure of hydrogen peroxide (H2O2) containing influent to ultraviolet (UV) lamps as the source of radiation that can convert H2O2 to hydroxyl radicals (·OH), which oxidize organic pollutants. However, two factors prevent this process from being scaled down: the need to introduce H2O2, which requires special handling, and the use of bulky UV lamps, which have a high electric power consumption. In this work, an electrochemical cell was developed for the efficient in situ generation of H2O2 from water and atmospheric oxygen in a process called a two-electron oxygen reduction reaction (2e-ORR), so that the external addition of H2O2 is no longer needed. Moreover, the electrochemical cell was equipped with ultraviolet light-emitting diodes (UV-LEDs) to convert H2O2 to ·OH. The reactor exhibited a current efficiency of ∼90% for the H2O2 production at a flow rate of 50 mL min−1. The degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied at 277 nm based on different operational parameters, such as UV fluence rate, initial concentration, and initial pH. A high degradation of >70% was obtained at a UV output of 900 mW. Our approach, the first of its kind, has novel features applied, including: optimal radiation distribution in the reactor by applying a new UV source, UV-LEDs that offer much more control for the radiation profile in the reaction system compared to traditional UV lamps, controlled hydrodynamics by implementing special flow channels to provide a more uniform residence time and offer enhanced mixing, and integrating UV reactor and electrochemical cell in a single unit which could lead to superior performance and space efficiency of the device. These features make the device very suitable for point-of-use (POU) water treatment applications to eliminate both microbial and chemical contaminants.

A Rapid Method for Low Temperature Microencapsulation of Phase Change Materials (PCMs) Using a Coiled Tube Ultraviolet Reactor

Microencapsulation of phase change materials (PCMs) remain a suitable option within building materials, as they contribute to the thermal mass and provide an energy buffer, an added benefit. This paper presents a novel method for the rapid fabrication of microencapsulated phase change materials (PCMs) at ambient conditions in a perfluoroalkoxy (PFA) coiled tube ultraviolet (UV) reactor. The objective of this study was to optimize key parameters such as the product yield and quality of the as-prepared microcapsules. Rubitherm® RT-21™ PCM was microencapsulated within shells of poly-methyl-methacrylate (PMMA) through a suspension emulsion polymerization approach, where the crosslinking of polymers was driven by UV radiations with an appropriate photoinitiator. The characteristics of the resulting PCM microcapsules were found to be affected by the volumetric flow rate of the emulsion inside the coiled tube reactor. Higher volumetric flow rates led to higher PCM contents and higher microencapsulation efficiency, resulting in an average particle size of 6.5 µm. Furthermore, the effect of curing time on the PCM microcapsule properties was investigated. The optimum encapsulation yield, conversion, efficiency and PCM content were observed after 10 min of polymerization time. The thermal analysis indicated that the developed process had an efficiency of 85.8%, and the capsules were characterized with excellent thermal properties. Compared to the conventional thermal microencapsulation processes, the use of a coiled tube UV reactor with an appropriate photoinitiator enables the encapsulation of heat-sensitive PCMs at ambient conditions, and reduces the microencapsulation time dramatically. As a result, this novel microencapsulation approach can lead to a wider scope of PCM encapsulation and enable rapid, continuous and potentially large-scale industrial production of PCM microcapsules with low energy consumption.

Woven-Fiber Microfiltration (WFMF) and Ultraviolet Light Emitting Diodes (UV LEDs) for Treating Wastewater and Septic Tank Effluent

Decentralized wastewater treatment systems enable wastewater to be treated at the source for cleaner discharge into the environment, protecting public health while allowing for reuse for agricultural and other purposes. This study, conducted in Thailand, investigated a decentralized wastewater treatment system incorporating a physical and photochemical process. Domestic wastewater from a university campus and conventional septic tank effluent from a small community were filtered through a woven-fiber microfiltration (WFMF) membrane as pretreatment for ultraviolet (UV) disinfection. In domestic wastewater, WFMF reduced TSS (by 79.8%), turbidity (76.5%), COD (38.5%), and NO3 (41.4%), meeting Thailand irrigation standards for every parameter except BOD. In septic tank effluent, it did not meet Thailand irrigation standards, but reduced TSS (by 77.9%), COD (37.6%), and TKN (13.5%). Bacteria (total coliform and Escherichia coli) and viruses (MS2 bacteriophage) passing through the membrane were disinfected by flow-through UV reactors containing either a low-pressure mercury lamp or light-emitting diodes (LEDs) emitting an average peak wavelength of 276 nm. Despite challenging and variable water quality conditions (2% < UVT < 88%), disinfection was predictable across water types and flow rates for both UV sources using combined variable modeling, which enabled us to estimate log inactivation of other microorganisms. Following UV disinfection, wastewater quality met the WHO standards for unrestricted irrigation.

A risk model for Escherichia coli survival in a sequential sand-filter (SF) and turbulent flow annular-reactor with ultraviolet irradiation (UV) for potable water production

The presence of suspended solids (SS) in raw feed-water can reduce the efficacy of Ultraviolet (UV) irradiation (Chem. Eng. Sci. 143 (2016) 55–62). Therefore, an integrated SS pre-treatment with rapid sand-filters (SF) is sometimes used. Here we synthesize for the first time a Fr 13 risk assessment of a two-step integrated SF with a UV reactor (SF-UV). The aim was to simulate how stochastic fluctuations in steady-state plant parameters could impact UV efficacy for potable water production. Failure of the SF-UV is defined as unwanted survival of viable Escherichia coli. Results show the overall failure of SF-UV operations is 40.4% which equates to 148 failures per annum. The mean reduction in SS in the SF was log10 −1.11 (90%), with a subsequent reduction in viable E. coli in the UV reactor of log10 −2.93 (99.9%). SF-UV is shown to be a combination of successful and failed operations and not all failed SF automatically result in failure in overall SF-UV efficacy. The second-tier simulation showed that the greater the safety tolerance the greater the loss of flexibility in SF-UV reactor. A precision feed-water flow control is needed to minimize underlying vulnerability to unexpected failure. This work will be of immediate interest to risk analysts, benefiting operators and managers responsible for producing potable water using UV irradiation.

Computational analysis of three lamp close conduit water disinfection UV reactor

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−e 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.

Revealing photon transmission in an ultraviolet reactor: Advanced approaches for measuring fluence rate distribution in water for model validation

Fluence rate (FR) distribution (optical field) is of great significance in the optimal design of ultraviolet (UV) reactors for disinfection or oxidation processes in water treatment. Since the 1970s, various simulation models have been developed, which can be combined with computational fluidic dynamic software to calculate the fluence delivered in a UV reactor. These models strive for experimental validation and further improvement, which is a major challenge for UV technology in water treatment. Herein, a review of the simulation models of the FR distribution in a UV reactor and the applications of the current main experimental measurement approaches including conventional flat-type UV detector, spherical actinometer, and micro-fluorescent silica detector (MFSD), is presented. Moreover, FR distributions in a UV reactor are compared between various simulation models and MFSD measurements. In addition, the main influential factors on the FR distribution, including inner-wall reflection, refraction and shadowing effects of adjacent lamps, and turbidity effect are discussed, which is helpful for improving the accuracy of the simulation models and avoiding dark regions in the reactor design. This paper provides an overview on the simulation models and measurement approaches for the FR distribution, which is helpful for the model selection in fluence calculations and gives high confidence on the optimal design of UV reactors in regard to present methods.

UV-C Treatment of Apple and Grape Juices by Modified UV-C Reactor Based on Dean Vortex Technology: Microbial, Physicochemical and Sensorial Parameters Evaluation

A laboratory-scale ultraviolet (UV-C) reactor based on Dean vortex technology was designed and tested for its capability to inactivate microorganisms in apple and red grape juices in relatively low doses of UV-C. Experiments were carried out with freshly squeezed apple juice (AJ) and freshly squeezed grape juice (GJ) inoculated with Lactobacillus plantarum NRIC1749 and Saccharomyces cerevisiae NCIB4932. Furthermore, physicochemical properties, antioxidant activity, total phenolic content, 5-HMF and colour analysis were performed in freshly squeezed apple (AJ) and grape juices (GJ). A UV-C treatment with 1668 mJ cm−2 led to an approximately 4.07-log inactivation of Lactobacillus plantarum NRIC1749 and 1.79-log inactivation of Saccharomyces cerevisiae NCIB4932 in AJ. A 0.69-log and 0.46-log reduction could be achieved for the inactivation of L. plantarum and S. cerevisiae in GJ at 1232 mJ cm−2, respectively. DPPH radical scavenging activity and total phenolic content of UV-C treated apple juice significantly increased, whereas total phenolic content remained constant in GJ. However, UV-C treatment had no significant effect on 5-HMF content of both juices. An effect of the treatment on the colour of both juices was observed. No significant change in the quality attributes (appearance, colour, odour, taste) was determined in the both UV-C treated juices.

Effects of Various Energy Suppliers in Green Processes for Obtaining Silver Nanoparticles

AbstractThe productions of stable suspensions of silver nanoparticles using a microwave reactor, an ultraviolet (UV) reactor, a low‐frequency low‐temperature plasma reactor, a high‐pressure reactor, and an open reactor are compared. All reactors served as sources of energy for stimulating the nanoparticle growth process. The silver nanoparticles were obtained based on the chemical reduction method. The processes were conducted using gallic acid as the reducing‐stabilizing substance. The influence of the variable parameters time (for all types of reactors), temperature (for the open and high‐pressure reactors), power (for the microwave reactor), energy density (for the UV reactor), and voltage (for the low‐frequency low‐temperature plasma reactor) was investigated. Temperature was found to be the most important factor influencing all processes.

Effect of highly reflective material on the performance of water ultraviolet disinfection reactor

The use of materials with high reflectivity on the surfaces of inner walls plays a significant role in enhancing the performance of ultraviolet (UV) reactors. In this study, the reactor efficiency is evaluated by changing the materials of the inner wall surfaces of the multi-lamp reactor from stainless steel to aluminum. The effect of water UV transmittance, flow rate, lamp power, and different modes of active lamps is studied on the effectiveness of inner wall reflection. Four turbulence models including standard k-ε, realizable k-ε, standard k-ω and SST k-ω, are used for the simulation of the flow field in a cross-flow UV reactor. The discrete ordinates model is applied to calculate the UV radiation field. The prediction of the velocity field showed that the SST k-ω model fits better with the experimental data. The results showed that if the inner wall is made of aluminum, the effect of reflection on the reactor performance increases with increasing UV transmittance and lamp power and decreasing flow rate. Investigations on lamp position showed that the effect of reflectivity becomes more apparent by reducing the lamp distance from the inner wall. Therefore, the reactor performance improvement is about 87–91% by putting the lamps closer to the wall and changing the wall material from stainless steel to aluminum.

Investigations on Ozone-Based and UV/US-Assisted Synergistic Digestion Methods for the Determination of Total Dissolved Nitrogen in Waters

Over the past two decades, the alkaline persulfate oxidation (PO) with thermal and/or ultraviolet (UV) assisted digestion method has been widely used for digestion of nitrogen containing compounds (N-compounds) in water quality routine analysis in laboratory or on-line analysis, due to its simple principle, high conversion rate, high percent recovery, low-cost. However, this digestion method still has some inevitable problems such as complex operations, high contamination potential, batch N blanks, higher reaction temperature (120–124 °C) and time-consuming (30–60 min). In this study, ozone (O3) was selected as the oxidant for digestion of N-compounds through analysis and comparison firstly. Secondly, we proposed and compared the UV and/or ultrasound (US) combined with ozone (UV/O3, US/O3 and UV/US/O3) synergistic digestion methods based on O3 with sole O3 oxidation method on digestion efficiency (digestion time and conversion rate) of standard N-compounds. Simultaneously, the influence of reaction temperature, pH of water sample, concentration of O3 and mass flow rate, UV intensity, US frequency and power on digestion efficiency were investigated, and then the optimum parameters for digestion system were obtained. Experimental results indicated that UV radiation can effectively induce and promote the decomposition and photolysis of O3 in water to generate hydroxyl radicals (•OH), while US can promote the diffusion and dissolution of O3 in water and intensify the gas-liquid mass transfer process for the reaction system. Meanwhile, results showed that the UV/US/O3 synergistic digestion method had the best digestion efficiency under the optimum conditions: water sample volume, 10 mL; pH of water sample, 11; O3 mass flow rate, 3200 mg/h; reaction temperature, 30 °C; digestion time, 25 min; UV lamp power, 18 W; distance between UV lamp and reactor, 2 cm; US frequency, 20 kHz; US power, 75 W. The conversion rate (CR) of synthetic wastewater samples varied from 99.6% to 101.4% for total dissolved nitrogen (TDN) in the range of 1.0~4.0 mg/L. The UV/US/O3 synergistic digestion method would be an effective and potential alternative for digestion of N-compounds in water quality routine analysis in laboratory or on-line analysis.

Inactivation of the multi-drug-resistant pathogen Candida auris using ultraviolet germicidal irradiation

Candida auris, often a multi-drug resistant fungal pathogen, has become an emerging threat in healthcare settings around the world. Reliable disinfection protocols specifically designed to inactivate C. auris are essential, as many chemical disinfectants commonly used in healthcare settings have been shown to have variable efficacy at inactivating C. auris. Ultraviolet germicidal irradiation (UVGI) was investigated as a method to inactivate clinically relevant strains of C. auris. Ten C. auris and two C. albicans isolates were exposed to ultraviolet (UV) energy to determine the UV dose required to inactivate each isolate. Using a UV reactor, each isolate (106 cells/mL) was exposed to 11 UV doses ranging from 10-150 mJ/cm2 and then cultured to assess cell viability. An exponential decay model was applied to each dose-response curve to determine inactivation rate constants for each isolate, which ranged from 0.108-0.176 cm2/mJ for C. auris and 0.239-0.292 cm2/mJ for C. albicans. As the model of exponential decay did not accurately estimate the dose beyond 99.9% inactivation, a logistic regression model was applied to better estimate the doses required for 99.999% inactivation. Using this model, significantly greater UV energy was required to inactivate C. auris (103 to 192 mJ/cm2) when compared to C. albicans (78 to 80 mJ/cm2). This study demonstrated UVGI as a feasible approach for inactivating C. auris, although variable susceptibility among isolates must be taken into account. This dose-response data is critical for recommending UVGI dosing strategies to be tested in healthcare settings.