scholarly journals H2S Removal from Groundwater by Chemical Free Advanced Oxidation Process Using UV-C/VUV Radiation

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4016
Author(s):  
Yael Gilboa ◽  
Yuval Alfiya ◽  
Sara Sabach ◽  
Eran Friedler ◽  
Yael Dubowski
Keyword(s):  
Advanced Oxidation Process ◽  
Flow Reactor ◽  
Advanced Oxidation ◽  
Anthropogenic Activity ◽  
Solid Catalysts ◽  
Adverse Health Effects ◽  
Hydrogen Sulfide Removal ◽  
Indirect Photolysis ◽  
Free Treatment ◽  
Uv C

Sulfide species may be present in groundwater due to natural processes or due to anthropogenic activity. H2S contamination poses odor nuisance and may also lead to adverse health effects. Advanced oxidation processes (AOPs) are considered promising treatments for hydrogen-sulfide removal from water, but conventional AOPs usually require continuous chemical dosing, as well as post-treatment, when solid catalysts are applied. Vacuum-UV (VUV) radiation can generate ·OH in situ via water photolysis, initiating chemical-free AOP. The present study investigated the applicability of VUV-based AOP for removal of H2S both in synthetic solutions and in real groundwater, comparing combined UV-C/VUV and UV-C only radiation in a continuous-flow reactor. In deionized water, H2S degradation was much faster under the combined radiation, dominated by indirect photolysis, and indicated the formation of sulfite intermediates that convert to sulfate at high radiation doses. Sulfide was efficiently removed from natural groundwater by the two examined lamps, with no clear preference between them. However, in anoxic conditions, common in sulfide-containing groundwater, a small advantage for the combined lamp was observed. These results demonstrate the potential of utilizing VUV-based AOP for treating H2S contamination in groundwater as a chemical-free treatment, which can be especially attractive to remote small treatment facilities.

scholarly journals Decontamination of N95 and surgical masks using a treatment based on a continuous gas phase-Advanced Oxidation Process

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248487
Author(s):  
Mahdiyeh Hasani ◽  
Tracey Campbell ◽  
Fan Wu ◽  
Keith Warriner
Keyword(s):  
Hydrogen Peroxide ◽  
Gas Phase ◽  
Hydroxyl Radicals ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Continuous Process ◽  
Oxidative Polymerization ◽  
Advanced Oxidation ◽  
Surgical Masks ◽  
Uv C

A gas-phase Advanced Oxidation Process (gAOP) was evaluated for decontaminating N95 and surgical masks. The continuous process was based on the generation of hydroxyl-radicals via the UV-C (254 nm) photo-degradation of hydrogen peroxide and ozone. The decontamination efficacy of the gAOP was dependent on the orientation of the N95 mask passing through the gAOP unit with those positioned horizontally enabling greater exposure to hydroxyl-radicals compared to when arranged vertically. The lethality of gAOP was independent of the applied hydrogen peroxide concentration (2–6% v/v) but was significantly (P<0.05) higher when H2O2 was introduced into the unit at 40 ml/min compared to 20 ml/min. A suitable treatment for N95 masks was identified as 3% v/v hydrogen peroxide delivered into the gAOP reactor at 40 ml/min with continuous introduction of ozone gas and a UV-C dose of 113 mJ/cm2 (30 s processing time). The treatment supported >6 log CFU decrease in Geobacillus stearothermophilus endospores, > 8 log reduction of human coronavirus 229E, and no detection of Escherichia coli K12 on the interior and exterior of masks. There was no negative effect on the N95 mask fitting or particulate efficacy after 20 passes through the gAOP system. No visual changes or hydrogen peroxide residues were detected (<1 ppm) in gAOP treated masks. The optimized gAOP treatment could also support >6 log CFU reduction of endospores inoculated on the interior or exterior of surgical masks. G. stearothermophilus Apex spore strips could be applied as a biological indicator to verify the performance of gAOP treatment. Also, a chemical indicator based on the oxidative polymerization of pyrrole was found suitable for reporting the generation of hydroxyl-radicals. In conclusion, gAOP is a verifiable treatment that can be applied to decontaminate N95 and surgical masks without any negative effects on functionality.

scholarly journals Degradation rates of benzotriazoles and benzothiazoles under UV-C irradiation and the advanced oxidation process UV/H2O2

2015 ◽  
Vol 74 ◽  
pp. 143-154 ◽  
Author(s):  
Sabrina Bahnmüller ◽  
Clara H. Loi ◽  
Kathryn L. Linge ◽  
Urs von Gunten ◽  
Silvio Canonica
Keyword(s):  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Advanced Oxidation ◽  
Degradation Rates ◽  
Uv C

scholarly journals A Novel Technique Using Advanced Oxidation Process (UV-C/H2O2) Combined with Micro-Nano Bubbles on Decontamination, Seed Viability, and Enhancing Phytonutrients of Roselle Microgreens

Horticulturae ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 53
Author(s):  
Surisa Phornvillay ◽  
Suwanan Yodsarn ◽  
Jiraporn Oonsrithong ◽  
Varit Srilaong ◽  
Nutthachai Pongprasert
Keyword(s):  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Microbiological Quality ◽  
Advanced Oxidation ◽  
Ascorbic Acid Content ◽  
Biochemical Properties ◽  
Total Phenolic ◽  
E Coli ◽  
Hydroxy Radicals ◽  
Uv C

Microbial contamination commonly occurs in microgreens due to contaminated seeds. This study investigated the decontamination effects of water wash (control), 5% hydrogen peroxide (H2O2), UV-C (36 watts), advanced oxidation process (AOP; H2O2 + UV-C), and improved AOP by combination with microbubbles (MBs; H2O2 + MBs and H2O2 + UV-C + MBs) on microbial loads, seeds’ viability, and physio-biochemical properties of microgreens from corresponding roselle seeds. Results showed that H2O2 and AOP, with and without MBs, significantly reduced total aerobic bacteria, coliforms, Escherichia coli (E. coli), and molds and yeast log count in seeds as compared to the control. Improved AOP treatment of H2O2 + UV-C + MBs significantly augmented antimicrobial activity against total bacteria and E. coli (not detected,) as compared to control and other treatments due to the formation of the highest hydroxy radicals (5.25 × 10−13 M). Additionally, H2O2 and combined treatments promoted seed germination, improved microbiological quality, total phenolic, flavonoids, and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) activity of the grown microgreens. Ascorbic acid content was induced only in microgreens developed from H2O2-treated seeds. Single UV-C treatment was ineffective to inactivate the detected microorganism population in seeds. These findings demonstrated that improved AOP treatment (H2O2 + UV-C + MBs) could potentially be used as a new disinfection technology for seed treatment in microgreens production.

scholarly journals ESTUDIO DE LA DECOLORACIÓN DEL COLORANTE SUNFIX YELLOW S4GL EMPLEANDO EL PROCESO DE OXIDACIÓN AVANZADA H2O2/UV

2018 ◽  
Vol 27 (1) ◽  
pp. 67
Author(s):  
Aldeir Pinedo ◽  
Fernando Anaya
Keyword(s):  
Hydrogen Peroxide ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Advanced Oxidation ◽  
Reactive Dye ◽  
Order Kinetic ◽  
Initial Concentration ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Uv C

Se ha realizado el estudio cinético de la decoloración del colorante reactivo Sunfix Yellow S4GL (RAS) empleando una disolución de 20 ppm del colorante mediante el proceso de oxidación avanzada (POA) H2O2/UV. Para ello se evaluó el efecto de la concentración inicial del peróxido de hidrógeno, el pH inicial de la solución, la concentración del colorante y la intensidad de la radiación UV‐C sobre la decoloración con el fin de optimizarlos. Los valores óptimos son los siguientes: concentración inicial de H2O2 a 3.8 x 10‐2 mol/L, pH3, concentración inicial del colorante a 20mg/L, potencia de radiación 3 lámparas con potencia de 15W de radiación UV‐C cada una. El estudio cinético de la decoloración sigue un modelo cinético de pseudo primer orden. Bajo condiciones óptimas se obtuvo un porcentaje de decoloración del 100% luego de una hora de tratamiento. Palabras clave.- decoloración, proceso de oxidación avanzada (POA), peróxido de hidrógeno, radiación UV‐C em> ABSTRACT A study of the kinetics of discoloration of a 20 ppm solution of Sunfix Yellow S4GL (RAS) reactive dye has been carried out using the H2O2/UV advanced oxidation process (AOP). To optimize the process, the effects on the discoloration of the initial concentration of hydrogen peroxide, the initial pH of the solution, the dye concentration and the intensity of the UV‐ C radiation were evaluated. The optimum values were the following: initial concentration of H2O2 a 3.8 x 10‐2 mol/L, pH3; initial dye concentration: 20 mg/L; UV radiation: 3 bulbs with 15 W of UV‐C power each. The discoloration reaction followed a pseudo first order kinetic model. Under optimum conditions, a one hour treatment yielded 100% discoloration. Keywords.- discoloration, advanced oxidation process (AOP), hydrogen peroxide, UV‐C radiation.

scholarly journals Methotrexate Degradation by UV-C and UV-C/TiO2 Pro-cesses with and without H2O2 Addition on Pilot Reactors

2020 ◽  
Vol 11 (10) ◽  
pp. 471-476
Author(s):  
L. A. González-Burciaga ◽  
◽  
J. C. García-Prieto ◽  
C. M. Núñez-Núñez ◽  
M. García-Roig ◽  
...  
Keyword(s):  
Advanced Oxidation Processes ◽  
Advanced Oxidation Process ◽  
Advanced Oxidation ◽  
Heterogeneous Photocatalysis ◽  
Cancer Drug ◽  
Starting Compound ◽  
Anti Cancer ◽  
Initial Ph ◽  
Feasible Alternative ◽  
Uv C

Methotrexate (MTX) is an anti-cancer drug that can be excreted up to 90% after administration due to its low biodegradability. Advanced Oxidation Processes (AOPs) are a feasible alternative for the elimination of MTX in the environment. In this research, AOPs were performed in specialized patented reactors (UBE Photocatalytic systems and BrightWater Titanium Advanced Oxidation Process) under experimental pilot conditions. Photolysis and heterogeneous photocatalysis (UV and UV/TiO2) experiments were performed with and without addition of H2O2 and at different initial pHs. Best degradation percentage was achieved by photolysis when initial pH was 3.5 and added H2O2 was 3 mM, reaching a MTX degradation of 82% after 120 min of reaction. HPLC-MS analysis of the resulting samples showed four possible byproducts of MTX degradation, which presented a higher ecotoxicity than the starting compound.

Influence of mineral water constituents, organic matter and water matrices on the performance of the H2O2/IO4−-advanced oxidation process

2019 ◽  
Vol 5 (11) ◽  
pp. 1985-1992 ◽  
Author(s):  
Nor Elhouda Chadi ◽  
Slimane Merouani ◽  
Oualid Hamdaoui ◽  
Mohammed Bouhelassa ◽  
Muthupandian Ashokkumar
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Mineral Water ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Advanced Oxidation ◽  
Water Constituents

We have recently reported that the reaction of H2O2/IO4− could be a new advanced oxidation process for water treatment [N. E. Chadi, S. Merouani, O. Hamdaoui, M. Bouhelassa and M. Ashokkumar, Environ. Sci.: Water Res. Technol., 2019, 5, 1113–1123].

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