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Uv light disinfection

Katelyn C Jelden, Shawn G Gibbs, Philip W Smith, Angela L Hewlett, Peter C Iwen, Kendra K Schmid, John J Lowe
An ultraviolet germicidal irradiation (UVGI) generator (the TORCH™, ClorDiSys Solutions, Inc.) was used to compare the disinfection of surface coupons (plastic from a bedrail, stainless steel, and chrome-plated light switch cover) in a hospital room with walls coated with ultraviolet (UV)-reflective paint (Lumacept) or standard paint. Each surface coupon was inoculated with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus faecalis (VRE), placed at 6 different sites within a hospital room coated with UV-reflective paint or standard paint, and treated by 10 minute UVC exposure (UVC dose of 0-688 mJ/cm(2) between sites with standard paint and 0-553 mJ/cm(2) with UV-reflective paint) in 8 total trials...
February 28, 2017: Journal of Occupational and Environmental Hygiene
Stephanie L Gora, Susan A Andrews
Titanium dioxide is a photocatalyst that can remove organic contaminants of interest to the drinking water treatment industry, including natural organic matter (NOM) and disinfection byproduct (DBP) precursors. The photocatalytic reaction occurs in two steps: adsorption of the contaminant followed by degradation of the adsorbed contaminant upon irradiation with UV light. The second part of this process can lead to the formation of reactive intermediates and negative impacts on treated water quality, such as increased DBP formation potential (DBPfp)...
May 2017: Chemosphere
John Ashley, Julia A Rasooly, Ian Tran, Lawrence E Yost, Glenn M Chertow
We evaluated the microbiological performance of an ultraviolet (UV) light-based peritoneal dialysis catheter connection system. The system includes a UV light-generating device combined with a UV transmissive window incorporated into the transfer set. Each UV transparent transfer set was inoculated with 10 μL of cultured inoculum consisting of either S. aureus, E. coli, or C. albicans After being inoculated, we attached a solution set connector to the transfer catheter, and exposed that connection to a UV light dose of approximately 340 mJoules/cm(2) After exposure to UV light, we broke the seal of the solution set and opened the plunger valve on the UV transmissive transfer catheter...
January 2017: Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis
Deverick J Anderson, Luke F Chen, David J Weber, Rebekah W Moehring, Sarah S Lewis, Patricia F Triplett, Michael Blocker, Paul Becherer, J Conrad Schwab, Lauren P Knelson, Yuliya Lokhnygina, William A Rutala, Hajime Kanamori, Maria F Gergen, Daniel J Sexton
BACKGROUND: Patients admitted to hospital can acquire multidrug-resistant organisms and Clostridium difficile from inadequately disinfected environmental surfaces. We determined the effect of three enhanced strategies for terminal room disinfection (disinfection of a room between occupying patients) on acquisition and infection due to meticillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, C difficile, and multidrug-resistant Acinetobacter. METHODS: We did a pragmatic, cluster-randomised, crossover trial at nine hospitals in the southeastern USA...
February 25, 2017: Lancet
Jun Deng, Jialiang Liang, Mian Li, Meiping Tong
g-C3N4-AgBr was synthesized by depositing AgBr nanoparticles onto g-C3N4. Scanning electron microscopy (SEM), Transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (DRS) and Photoluminescence (PL) spectra were employed to characterize the as-synthesized photocatalysts. The disinfection activities towards representative Gram-negative strain E. coli and Gram-positive strain S. aureus were examined under visible light irradiation...
April 1, 2017: Colloids and Surfaces. B, Biointerfaces
Peizhe Sun, Wan-Ning Lee, Ruochun Zhang, Ching-Hua Huang
Photoactivation of aqueous chlorine could promote degradation of chlorine-resistant and photochemically stable chemicals accumulated in swimming pools. This study investigated the degradation of two such chemicals, N,N-diethyl-3-methylbenzamide (DEET) and caffeine, by low pressure ultraviolet (UV) light and simulated sunlight (SS) activated free chlorine (FC) in different water matrices. Both DEET and caffeine were rapidly degraded by UV/FC and SS/FC but exhibited different kinetic behaviors. The degradation of DEET followed pseudo-first-order kinetics, whereas the degradation of caffeine accelerated with reaction...
December 20, 2016: Environmental Science & Technology
A Shirai, T Watanabe, H Matsuki
The low energy of UV-A (315-400 nm) is insufficient for disinfection. To improve UV-A disinfection technology, we evaluated the effect of ferulic acid (FA) addition on disinfection by UV-A light-emitting diode (LED) (350-385 nm) against various food spoilers and pathogens (seven bacteria and four fungi species). Photoantimicrobial assays were performed at FA concentrations below the MIC. The MIC of the isomerized FA, consisting of 93% cis-form and 7% trans-form, was very similar to that of the commercially available FA (trans-form)...
February 2017: Letters in Applied Microbiology
M Hessling, B Spellerberg, K Hoenes
Visible light has strong disinfectant properties, a fact which is not well known in comparison to the antibacterial properties of UV light. This review compiles the published data on bacterial inactivation caused by visible light and endogenous photosensitizers. It evaluates more than 100 published studies containing information on about 40 different bacterial species irradiated within the spectral range from 380 to 780 nm. In the available data a high variability of the photoinactivation sensitivity is observed, which may be caused by undefined illumination conditions...
December 2, 2016: FEMS Microbiology Letters
Xiaoqin Zhou, Zifu Li, Juanru Lan, Yichang Yan, Nan Zhu
Ultraviolet (UV) disinfection is highly recommended owing to its high disinfection efficiency and disinfection by-products free, and UV Light-Emitting Diodes (UV LEDs) is increasingly becoming an alternative of mercury UV lamps for water disinfection owing to its long lifetime, low input power, and absence of problems on disposal. However, renovation of existing UV lamps faces the challenges for UV disinfection associated with disinfection efficiency and photoreactivation, and modified UV disinfection process is required for practical application...
March 2017: Ultrasonics Sonochemistry
Kai Ouyang, Ke Dai, Hao Chen, Qiaoyun Huang, Chunhui Gao, Peng Cai
Interest has grown in developing safe and high-performance photocatalysts based on metal-free materials for disinfection of bacterial pathogens under visible light irradiation. In this paper, the C60/C3N4 and C70/C3N4 hybrids were synthesized by a hydrothermal method, and characterized by X-ray diffraction (XRD), UV-vis diffuse reflection spectroscopy (UV-vis DRS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and high revolution transmission electron microscope (HRTEM)...
February 2017: Ecotoxicology and Environmental Safety
Nicole L McLellan, Hung Lee, Marc B Habash
Standardized and rapid assays for viable viral pathogens are needed to inform human health risk assessments. Conventional qPCR is designed to enumerate the gene copies of an organism in a sample, but does not identify those that originated from a viable pathogen. This study was undertaken to evaluate modified qPCR methods as infectivity assays for the enumeration of infectious MS2 coliphage. Propidium monoazide (PMA) treatment coupled with long-amplicon qPCR assays were assessed for their ability to quantify infectious MS2 in pure cultures and following inactivation by a range of UV light exposures and chlorine doses...
October 12, 2016: Journal of Virological Methods
Nazmiye Cemre Birben, Ayse Tomruk, Miray Bekbolet
Solar photocatalytic disinfection efficiency of novel visible light activated (VLA) photocatalysts was evaluated with the aim of assessing inactivation of Escherichia coli as the pathogen indicator organism present in drinking water. Influence of humic acid (HA) on the photocatalytic disinfection efficiency of the specified VLA TiO2 specimens i.e., N-doped, Se-doped, and Se-N co-doped TiO2 was also investigated. Photocatalytic disinfection efficiency was assessed by the enumeration of bacteria following selected irradiation periods...
October 6, 2016: Environmental Science and Pollution Research International
Daseul Park, Hafiz Muhammad Shahbaz, Sun-Hyoung Kim, Mijin Lee, Wooseong Lee, Jong-Won Oh, Dong-Un Lee, Jiyong Park
Human norovirus (HuNoV) is the primary cause of viral gastroenteritis worldwide. Fresh blueberries are among high risk foods associated with norovirus related outbreaks. Therefore, it is important to assess intervention strategies to reduce the risk of foodborne illness. The disinfection efficiency of decontamination methods is difficult to evaluate for fruits and vegetables due to an inconsistent degree of contamination and irregular surface characteristics. The inactivation efficiency and mechanism of murine norovirus 1 (MNV-1, a surrogate for HuNoV) was studied on an experimentally prepared solidified agar matrix (SAM) to simulate blueberries using different wavelengths (A, B, C) of UV light both with and without TiO2 photocatalysis (TP)...
December 5, 2016: International Journal of Food Microbiology
Fiona Zakaria, Bertin Harelimana, Josip Ćurko, Jack van de Vossenberg, Hector A Garcia, Christine Maria Hooijmans, Damir Brdjanovic
Ultraviolet germicidal (short wavelength UV-C) light was studied as surface disinfectant in an Emergency Sanitation Operation System(®) smart toilet to aid to the work of manual cleaning. The UV-C light was installed and regulated as a self-cleaning feature of the toilet, which automatically irradiate after each toilet use. Two experimental phases were conducted i.e. preparatory phase consists of tests under laboratory conditions and field testing phase. The laboratory UV test indicated that irradiation for 10 min with medium-low intensity of 0...
October 2016: International Journal of Environmental Health Research
Suqi Li, Jing Xu, Wei Chen, Yingtan Yu, Zizheng Liu, Jinjun Li, Feng Wu
p-Arsanilic acid (p-ASA) is widely used in China as livestock and poultry feed additive for promoting animal growth. The use of organoarsenics poses a potential threat to the environment because it is mostly excreted by animals in its original form and can be transformed by UV-Vis light excitation. This work examined the initial rate and efficiency of p-ASA phototransformation under UV-C disinfection lamp. Several factors influencing p-ASA phototransformation, namely, pH, initial concentration, temperature, as well as the presence of NaCl, NH4(+), and humic acid, were investigated...
September 2016: Journal of Environmental Sciences (China)
Andrea Di Cesare, Diego Fontaneto, Julia Doppelbauer, Gianluca Corno
Antibiotic resistance genes (ARGs) are increasingly appreciated to be important as micropollutants. Indirectly produced by human activities, they are released into the environment, as they are untargeted by conventional wastewater treatments. In order to understand the fate of ARGs and of other resistant forms (e.g., phenotypical adaptations) in urban wastewater treatment plants (WWTPs), we monitored three WWTPs with different disinfection processes (chlorine, peracetic acid (PAA), and ultraviolet light (UV))...
September 20, 2016: Environmental Science & Technology
Jialiang Liang, Jun Deng, Mian Li, Tongyan Xu, Meiping Tong
Ti doped BiOI microspheres were successfully synthesized through a solvothermal method. The photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectra (DRS) spectroscopy, respectively. The as-synthesized microspheres had 3D hierarchical structures, and the morphologies and visible-light-driven (VLD) disinfection performances were found to be determined by the amount of loaded Ti...
November 1, 2016: Colloids and Surfaces. B, Biointerfaces
Edson Baltazar Estrada-Arriaga, Juana Enriqueta Cortés-Muñoz, Arturo González-Herrera, César Guillermo Calderón-Mólgora, Ma de Lourdes Rivera-Huerta, Esperanza Ramírez-Camperos, Leticia Montellano-Palacios, Silvia Lucila Gelover-Santiago, Sara Pérez-Castrejón, Lina Cardoso-Vigueros, Alejandra Martín-Domínguez, Liliana García-Sánchez
Two full-scale biological nutrient removal systems upgraded with three physico-chemical processes (coagulation, chemical precipitation, and neutral Fenton) were evaluated in order to determine the removal of emerging pollutants (EPs) present in municipal wastewater from Mexico. Between 41 and 55 EPs were detected in the influents of two wastewater treatment plants (WWTPs), including personal care products (PPCPs), antibiotics, analgesics, antiepileptics, antilipidemics, antihypertensives, antiseptics, stimulants, and hormones...
November 15, 2016: Science of the Total Environment
Maria Laura Luprano, Marco De Sanctis, Guido Del Moro, Claudio Di Iaconi, Antonio Lopez, Caterina Levantesi
In order to mitigate the potential effects on the human health which are associated to the use of treated wastewater in agriculture, antibiotic resistance genes (ARGs) are required to be carefully monitored in wastewater reuse processes and their spread should be prevented by the development of efficient treatment technologies. Objective of this study was the assessment of ARGs reduction efficiencies of a novel technological treatment solution for agricultural reuse of municipal wastewaters. The proposed solution comprises an advanced biological treatment (Sequencing Batch Biofilter Granular Reactor, SBBGR), analysed both al laboratory and pilot scale, followed by sand filtration and two different disinfection final stages: ultraviolet light (UV) radiation and peracetic acid (PAA) treatments...
November 15, 2016: Science of the Total Environment
Stefanos Giannakis, Margaux Voumard, Dominique Grandjean, Anoys Magnet, Luiz Felippe De Alencastro, César Pulgarin
In this work, disinfection by 5 Advanced Oxidation Processes was preceded by 3 different secondary treatment systems present in the wastewater treatment plant of Vidy, Lausanne (Switzerland). 5 AOPs after two biological treatment methods (conventional activated sludge and moving bed bioreactor) and a physiochemical process (coagulation-flocculation) were tested in laboratory scale. The dependence among AOPs efficiency and secondary (pre)treatment was estimated by following the bacterial concentration i) before secondary treatment, ii) after the different secondary treatment methods and iii) after the various AOPs...
October 1, 2016: Water Research
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