Behavior of Carbamzepine, Clofibric Acid, Iomeprol, Iopromide in the Environment – Photochemical Degradation by Simulated Solar UV‐Light

Vom Wasser ◽  
2003 ◽  
pp. 99-110 ◽  
Author(s):  
Tusnelda E. Doll ◽  
Fritz H. Frimmel
Keyword(s):  
Uv Light ◽  
Clofibric Acid ◽  
Photochemical Degradation ◽  
Solar Uv

scholarly journals Photodegradation of Trace Trichloronitromethane in Water under UV Irradiation

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Lin Deng ◽  
Zhiren Wu ◽  
Caiqian Yang ◽  
Yung-Li Wang
Keyword(s):  
Humic Acid ◽  
Light Intensity ◽  
Uv Light ◽  
Control Strategies ◽  
Chloride Ions ◽  
Source Control ◽  
Photochemical Degradation ◽  
Nitrate Ions ◽  
Photodegradation Rate ◽  
Water And Wastewater

This study’s objective was to study the photodegradation of TCNM (trichloronitromethane) in water under UV light. The effects of light intensity, nitrate ions, chloride ions, humic acid, and pH on the photochemical degradation of TCNM were investigated under the irradiation of low pressure mercury lamp (λ= 254 nm, 12 W). The photodegradation rate of TCNM was found to increase with increasing the concentration of nitrate ions, chloride ions, humic acid, pH, and light intensity. The photodegradation of TCNM was examined at pH 6.0 with initial concentrations (C0) of TCNM at 10.0–200.0 µg/L. The overall rate of degradation of TCNM was modeled using a pseudofirst-order rate law. Finally, the proposed mechanism involved in the photodegradation of TCNM was also discussed by analysis. Results of this study can contribute to the development of new source control strategies for minimization of TCNM risk at drinking water and wastewater utilities.

scholarly journals Solar simulated ultraviolet radiation inactivates HCoV-NL63 and SARS-CoV-2 coronaviruses at environmentally relevant doses

2021 ◽  
Author(s):  
Georg T. Wondrak ◽  
Jana Jandova ◽  
Spencer J. Williams ◽  
Dominik Schenten
Keyword(s):  
Gene Expression ◽  
Stress Response ◽  
Uv Light ◽  
Gene Expression Array ◽  
Array Analysis ◽  
Expression Array ◽  
Response Gene ◽  
Full Spectrum ◽  
Solar Uv ◽  
Stress Response Gene

The germicidal properties of short wavelength ultraviolet C (UVC) light are well established and used to inactivate many viruses and other microbes. However, much less is known about germicidal effects of terrestrial solar UV light, confined exclusively to wavelengths in the UVA and UVB regions. Here, we have explored the sensitivity of the human coronaviruses HCoV-NL63 and SARS-CoV-2 to solar-simulated full spectrum ultraviolet light (sUV) delivered at environmentally relevant doses. First, HCoV-NL63 coronavirus inactivation by sUV-exposure was confirmed employing (i) viral plaque assays, (ii) RT-qPCR detection of viral genome replication, and (iii) infection-induced stress response gene expression array analysis. Next, a detailed dose-response relationship of SARS-CoV-2 coronavirus inactivation by sUV was elucidated, suggesting a half maximal suppression of viral infectivity at low sUV doses. Likewise, extended sUV exposure of SARS-CoV-2 blocked cellular infection as revealed by plaque assay and stress response gene expression array analysis. Moreover, comparative (HCoV-NL63 versus SARS-CoV-2) single gene expression analysis by RT-qPCR confirmed that sUV exposure blocks coronavirus-induced redox, inflammatory, and proteotoxic stress responses. Based on our findings, we estimate that solar ground level full spectrum UV light impairs coronavirus infectivity at environmentally relevant doses. Given the urgency and global scale of the unfolding SARS-CoV-2 pandemic, these prototype data suggest feasibility of solar UV-induced viral inactivation, an observation deserving further molecular exploration in more relevant exposure models.

scholarly journals Solar UV light regulates flavonoid metabolism in apple (Malus x domestica)

2018 ◽  
Vol 41 (3) ◽  
pp. 675-688 ◽  
Author(s):  
Rebecca A. Henry-Kirk ◽  
Blue Plunkett ◽  
Miriam Hall ◽  
Tony McGhie ◽  
Andrew C. Allan ◽  
...  
Keyword(s):  
Uv Light ◽  
Malus X Domestica ◽  
Flavonoid Metabolism ◽  
Solar Uv

scholarly journals Photochemical Degradation of Cyanides and Thiocyanates from an Industrial Wastewater

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1373 ◽  
Author(s):  
Juan Jose Viña Mediavilla ◽  
Begoña Fernandez Perez ◽  
Maria C. Fernandez de Cordoba ◽  
Julia Ayala Espina ◽  
Conchi O. Ania
Keyword(s):  
Uv Light ◽  
Degradation Mechanism ◽  
Industrial Effluents ◽  
Photochemical Oxidation ◽  
Solar Light ◽  
Photochemical Degradation ◽  
Simulated Solar Light ◽  
Cyanide Detoxification ◽  
Detoxification Systems ◽  
Recombination Reactions

We have explored the simultaneous degradation of cyanides and thiocyanate present in wastewaters from a cokemaking factory using photoassisted methods under varied illumination conditions (from simulated solar light to UV light). Overall, the photochemical degradation of cyanides was more efficient than that of thiocyanates, regardless of the illumination conditions, the effect being more pronounced in the absence of a photocatalyst. This is due to their different degradation mechanism that in the case of thiocyanates is dominated by fast recombination reactions and/or charge transfer reactions to electron scavengers. In all cases, cyanate, ammonia, nitrates, and nitrites were formed at different amounts depending on the illumination conditions. The conversion yield under simulated solar light was almost complete for cyanides and quite high for thiocyanates after 6 h of illumination. Regarding toxicity, photochemical oxidation at 254 nm and under simulated solar light decreased significantly the toxicity of the pristine wastewater, showing a correlation with the intensity of the irradiation source. This indicate that simulated light can be effectively used to reduce the toxicity of industrial effluents, opening an interesting perspective for optimizing cyanide detoxification systems based on natural light.

Effect of ammonium salts on the photochemical degradation of iron containing organic aerosol

2020 ◽  
Author(s):  
Ulrich Krieger ◽  
Nir Bluvshtein ◽  
Jing Dou
Keyword(s):  
Citric Acid ◽  
Gas Phase ◽  
Degradation Rate ◽  
Uv Light ◽  
Lower Troposphere ◽  
Organic Aerosol ◽  
Photochemical Degradation ◽  
Single Particles ◽  
Electrodynamic Balance ◽  
Humidity Dependence

<p>Formation of organic aerosol by oxidation of gas phase compounds has been intensely studied, and is much better understood than the aerosol ageing transformations during the lifetime of organic aerosol. Aerosol ageing influences how those aerosol particles affect climate and human health and is still not well constrained in current models.</p><p>Photochemistry in the condensed phase is an important mechanism responsible for ageing of organic aerosol. In the lower troposphere, where UV light intensity with sufficiently low wavelength to directly photolyze aerosol components is low, indirect photochemistry (catalyzing redox processes of non-absorbing molecules) is especially relevant. Recently we studied transition metal complex photochemistry in single particles levitated in an electrodynamic balance. In particular, we investigated the aqueous iron(III)-citrate/citric acid system and found that irradiation at 473 nm led to rapid and significant degradation of the citric acid. Up to 80% of the initial particle mass was partitioned to the gas phase with the degradation rate depending on kinetic transport limitations of oxygen. These kinetic limitations arise are influenced strongly by the relative humidity dependence of particle viscosity where water acts as a plasticizer.</p><p>Here we will report on photochemical degradation experiments adding various salts in different (ammonium sulfate, ammonium bisulfate, etc.) to the reference system iron(III)-citrate/citric acid. Preliminary experiments suggest that pH of the aerosol particle influences the degradation rate in this system significantly.</p>

Solar ultraviolet radiation dependent decrease of particle light absorption and pigments in lake phytoplankton

1997 ◽  
Vol 54 (3) ◽  
pp. 697-704 ◽  
Author(s):  
H Maske ◽  
M Latasa
Keyword(s):  
Light Absorption ◽  
Uv Light ◽  
Spectral Component ◽  
Ultraviolet B ◽  
Cutoff Wavelength ◽  
Solar Ultraviolet Radiation ◽  
Solar Uv ◽  
Band Pass ◽  
Solar Ultraviolet

The ultraviolet (UV) spectral component of daylight on a clear day at mid-latitudes can significantly reduce phytoplankton pigments within a daylight period. Phytoplankton samples from Redberry Lake, Saskatchewan, dominated by cyanobacteria were incubated in quartz bottles under optical long band-pass filters (cutoff wavelength 420-305 nm) in daylight in June. After incubation, samples were filtered, and in vivo particle light absorption (380-700 nm) and pigment concentrations were measured. Solar ultraviolet-B irradiance (UV-B; 280-320 nm) was measured radiometrically. On sunny days the samples that were exposed to daylight UV light showed a relative decrease in particle absorption and pigment concentration after the incubation compared with samples exposed only to visible daylight. No such decrease was observed during an overcast day. The UV-B data did not show a clear relation with the degree of pigment reduction, suggesting that other environmental factors or the state of adaptation partially controlled the pigment decrease of phytoplankton under UV-B exposure. Neither specific spectral components of the absorption spectrum nor specific pigments were more easily degraded than others by solar UV light, although the ratio of zeaxanthin to chlorophyll a probably increased in cyanobacteria as a result of UV exposure.

scholarly journals Formation of Secondary Organic Aerosols by Germicidal Ultraviolet Light

Environments ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 17
Author(s):  
Eureka Choi ◽  
Zhongchao Tan ◽  
William Anderson
Keyword(s):  
Uv Light ◽  
Fine Particulate Matter ◽  
Particle Formation ◽  
Uv Exposure ◽  
Indoor Environments ◽  
Fine Particulate ◽  
Volatile Organic ◽  
Solar Uv ◽  
Commercial Environment ◽  
Number Of Particles

Ultraviolet (UV) light with a wavelength of 254 nm is known to be germicidal, and thus has been increasingly employed as a method of disinfection for indoor environments. Solar UV wavelengths (300 to 400 nm) are known to initiate the formation of secondary organic aerosol (SOA) particles from the photo-oxidation of volatile organic compounds (VOC) in the atmosphere, but germicidal wavelengths have not been extensively studied for indoor environments. In this work, toluene was exposed to 254 nm UV light in a laboratory photoreactor while varying the conditions of the air, the duration of UV exposure, and the duration of post-UV time. The number of particles formed in the fine particulate matter (PM2.5) size range was measured, and significant levels of particle formation were observed for UV exposure periods of as short as 5 min. The particle formation ranged from 2.4 × 106 particles/m3 for 5 min of UV exposure, to 163.2 × 106 particles/m3 for 15 min of UV exposure, for toluene concentrations in the range of 55 to 85 mg/m3. Particle formation was found to increase at a relative humidity of approximately 20% and higher. Variations in the initial number of particles present did not appear to have a significant effect on the particle formation, suggesting that nucleation was not a controlling factor under these conditions. However, tests in a commercial environment at much lower VOC concentrations and lower UV fluence rates showed no detectable PM2.5 formation, indicating that SOA formation during the intermittent use of germicidal UV may not significantly affect indoor air quality under normal conditions.

Preparation of Functionalized Low Molecular Weight Natural Rubber Latex Using Solid Nanometric TiO3 Film as a Photocatalyst

2005 ◽  
Vol 78 (4) ◽  
pp. 597-605 ◽  
Author(s):  
Jitladdat Sakdapipanich ◽  
Patjaree Suksawad ◽  
Kittipong Insom ◽  
Seiichi Kawahara
Keyword(s):  
Molecular Weight ◽  
Natural Rubber ◽  
Uv Irradiation ◽  
Tio2 Film ◽  
Uv Light ◽  
Average Molecular Weight ◽  
Natural Rubber Latex ◽  
Petri Dish ◽  
Solution Viscosity ◽  
Photochemical Degradation

Abstract Natural rubber (NR) is a high molecular weight (MW) hydrophobic polymer, which can not be easily dissolved in several kinds of solvents, leading to the limitation of usage. NR latex containing low MW and reactive-terminal groups is another interesting form to extend the applications of NR. In this study, a photochemical degradation of NR using H2O2, nanometric TiO2 film and UV irradiation was applied to prepare the hydroxylated low MW NR (LNR). A solid nanometric TiO2 film prepared from titanium solution was applied in the present work. The photosensitivity of the self-assembled TiO2 film was determined by the decomposition rate of methylene blue stock solution using UV/VIS spectrophotometer. The effect of type of NR latex used, H2O2, UV light and TiO2 film on the molecular weight reduction was studied, based on change in intrinsic viscosity determined by Ubbelohde solution viscosity. The structural characterization of the resulting LNR was analyzed by FT-IR and NMR techniques. It was found that hydroxylated LNR with number average molecular weight of 1 × 104 g/mol was obtained by UV irradiation (40 W) of deproteinized natural rubber (DPNR) latex (10% DRC) containing 30% w/w H2O2, on a petri dish coated with TiO2 film for 5 hr. The advantage of this method is that the obtained hydroxylated LNR in either latex or dry rubber form is very clean without further purification.

scholarly journals Solar UV-B/A radiation is highly effective in inactivating SARS-CoV-2

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fabrizio Nicastro ◽  
Giorgia Sironi ◽  
Elio Antonello ◽  
Andrea Bianco ◽  
Mara Biasin ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Open Space ◽  
Uv Light ◽  
Rna Virus ◽  
Action Spectrum ◽  
Solar Irradiation ◽  
Mortality Data ◽  
Solar Uv ◽  
Solar Pump ◽  
Set Up

AbstractSolar UV-C photons do not reach Earth’s surface, but are known to be endowed with germicidal properties that are also effective on viruses. The effect of softer UV-B and UV-A photons, which copiously reach the Earth’s surface, on viruses are instead little studied, particularly on single-stranded RNA viruses. Here we combine our measurements of the action spectrum of Covid-19 in response to UV light, Solar irradiation measurements on Earth during the SARS-CoV-2 pandemics, worldwide recorded Covid-19 mortality data and our “Solar-Pump” diffusive model of epidemics to show that (a) UV-B/A photons have a powerful virucidal effect on the single-stranded RNA virus Covid-19 and that (b) the Solar radiation that reaches temperate regions of the Earth at noon during summers, is sufficient to inactivate 63% of virions in open-space concentrations (1.5 × 103 TCID50/mL, higher than typical aerosol) in less than 2 min. We conclude that the characteristic seasonality imprint displayed world-wide by the SARS-Cov-2 mortality time-series throughout the diffusion of the outbreak (with temperate regions showing clear seasonal trends and equatorial regions suffering, on average, a systematically lower mortality), might have been efficiently set by the different intensity of UV-B/A Solar radiation hitting different Earth’s locations at different times of the year. Our results suggest that Solar UV-B/A play an important role in planning strategies of confinement of the epidemics, which should be worked out and set up during spring/summer months and fully implemented during low-solar-irradiation periods.

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