scholarly journals Bromate Formation Characteristics of UV Irradiation, Hydrogen Peroxide Addition, Ozonation, and Their Combination Processes

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Naoyuki Kishimoto ◽  
Eri Nakamura
Keyword(s):  
Hydrogen Peroxide ◽  
Uv Irradiation

Photoreaktivierung von UV-inaktivierter Polyuridylsäure

1964 ◽  
Vol 19 (5) ◽  
pp. 406-408 ◽  
Author(s):  
Adolf Wacker ◽  
Makoto Ishimoto ◽  
Prakash Chandra ◽  
Reinhold Selzer
Keyword(s):  
Hydrogen Peroxide ◽  
Visible Light ◽  
Uv Irradiation ◽  
Trichloroacetic Acid ◽  
Uranyl Acetate ◽  
Free System ◽  
E Coli ◽  
Polyuridylic Acid ◽  
A Cell ◽  
The One

A study on the effect of UV-irradiated polyuridylic acid on the incorporation of phenylalanine into the polypeptide precipitable through trichloroacetic acid, in a cell-free system from E. coli was made. Attempts were made to reactivate the UV-inactivated polyuridylic acid through hydrogen peroxide, uranyl acetate and visible light. We could show that polyuridylic acid irradiated at a dose of 1.2 ×105 ergs/mm2 could be completely reactivated, while the one irradiated at a higher dose of 2.4 ×105 ergs/mm2 could not be completely reactivated under the conditions of our experiment. We have studied the effects of hydrogen peroxide and uranyl acetate on UV-irradiated polyuridylic acid chemically as well. Our results altogether show that the photoreactivating effect of uranyl acetate and hydrogen peroxide is due to their ability to split the uracil dimers formed during UV-irradiation.

Degradation of triethylene glycol dimethyl ether by ozonation combined with UV irradiation or hydrogen peroxide addition

1997 ◽  
Vol 36 (2-3) ◽  
pp. 131-138 ◽  
Author(s):  
V. Beschkov ◽  
G. Bardarska ◽  
H. Gulyas ◽  
I. Sekoulov
Keyword(s):  
Hydrogen Peroxide ◽  
Dimethyl Ether ◽  
Uv Irradiation ◽  
Biological Treatment ◽  
Triethylene Glycol ◽  
Uv Treatment ◽  
Glycol Dimethyl Ether ◽  
Small Doses ◽  
High Concentrations ◽  
Oxidized Products

Ozonation of pure aqueous solutions of the polar aliphatic refractory triethylene glycol dimethyl ether (TEGDME) which is a typical representative of organic solutes of oil reclaiming wastewaters does not lead to effective mineralization unless high ozone doses are applied. Small doses of UV irradiation do not markedly increase TEGDME mineralization by ozonation, but transformation to more oxidized products (mainly carboxylic acids containing methoxy and/or ethoxy groups) which are biodegradable to a higher degree than TEGDME. Addition of high concentrations of hydrogen peroxide during ozonation results in efficient increase of TEGDME mineralization, however. The presence of humic acids - which is a consequence of biological treatment of wastewaters containing biodegradable organic constituents - has a beneficial effect on transformation of TEGDME during ozonation or ozone/UV treatment because hydrogen peroxide is formed during ozonation of humic acid C-C double bonds.

Photocatalytic Clearing of Disperse Dyed Polyester

2019 ◽  
Vol 6 (5) ◽  
pp. 10-15 ◽  
Author(s):  
Semiha Eren
Keyword(s):  
Hydrogen Peroxide ◽  
Uv Irradiation ◽  
Room Temperature ◽  
Color Difference ◽  
Polyester Fabric ◽  
Disperse Dyes ◽  
Wash Fastness ◽  
Ph Values ◽  
Thiourea Dioxide ◽  
Color Differences

Trials were conducted to examine the efficiency of photocatalytic afterclearing on disperse dyed polyester. The photocatalytic afterclearing was performed by ultraviolet (UV) irradiation and hydrogen peroxide (H2O2). Polyester fabric samples were dyed with three disperse dyes at 4% depth of shade, individually. The control afterclearing treatment was a conventional reductive clearing by thiourea dioxide and caustic soda. The H2O2 impregnated samples, using various concentrations of H2O2 at various pH values, were treated under 254 nm UV irradiation (5, 10, 20, and 30 min) at room temperature. Color, color difference, wash fastness, and tensile strength values of the samples were compared. Photocatalytic clearing of disperse dyed polyester was successful in giving comparable wash fastness results as compared to conventional reduction clearing without significant color differences.

Fabrication of Smooth Surface on 4H-SiC Substrate by Ultraviolet Assisted Local Polishing in Hydrogen Peroxide Solution

2012 ◽  
Vol 523-524 ◽  
pp. 24-28 ◽  
Author(s):  
Akihisa Kubota ◽  
Kazuya Kurihara ◽  
Mutsumi Touge
Keyword(s):  
Hydrogen Peroxide ◽  
Oxide Layer ◽  
Uv Irradiation ◽  
Process Parameters ◽  
Removal Rate ◽  
Single Crystal Silicon ◽  
Interference Microscopy ◽  
Process Time ◽  
Crystal Silicon ◽  
Synthetic Quartz

In this study, we investigated the possibility of removing and smoothing a single-crystal silicon carbide (SiC) surface under ultraviolet (UV) irradiation in hydrogen peroxide (H2O2) solution. In this method, a SiC substrate was excited by UV irradiation that transmitted synthetic quartz, and then an oxide layer on the SiC substrate was formed by photochemical reaction. Simultaneously, hydroxyl radical (OH*) was generated by the decomposition of H2O2 solution by UV irradiation. OH* plays an important role of oxidation of SiC surface. With these chemical reactions, oxide layer was effectively formed on the SiC surface. Finally, the oxide layer generated on a SiC substrate was chemically and/or mechanically removed by synthetic quartz and solutions. The polishing characteristics of this method were investigated by controlling the process parameters. Additionally, surface quality and removal depth were measured and evaluated by a phase-shift interference microscopy. Obtained results show that the surface morphology and the removal rate are strongly dependent on the existence of the UV irradiation. Moreover, it is shown that the removal characteristics of the SiC substrate depend on the process parameters such as the process time, reciprocating speed, and contact load. The processed surface has revealed that many scratches on the preprocessed surface was completely removed. The microroughness of the processed surface was improved to 0.15 nm (Rms) and 1.62 nm (p-v), respectively. These results provide useful information for obtaining an atomically smooth SiC surface.

Degradation of Aflatoxin M1 in Milk by Ultraviolet Energy

1985 ◽  
Vol 48 (8) ◽  
pp. 697-698 ◽  
Author(s):  
AHMED E. YOUSEF ◽  
ELMER H. MARTH
Keyword(s):  
Hydrogen Peroxide ◽  
Uv Irradiation ◽  
Aflatoxin M1 ◽  
Experimental Conditions ◽  
Whole Milk ◽  
Ultraviolet Energy ◽  
Different Sources ◽  
Enhanced Degradation

Raw whole milk was artificially contaminated with 0.5 or 1 ppb aflatoxin M1. Contaminated milk was exposed to UV-irradiation from different sources and under different experimental conditions. In all instances, exposure to UV-irradiation caused aflatoxin M1 in milk to degrade. The magnitude of degradation (3.6 to 100%) depended on time of exposure (2 to 60 min) of milk to UV-energy, volume of treated milk and design of the experiment. Presence of hydrogen peroxide (1%) in milk greatly enhanced degradation (100% in 10 min) of aflatoxin M1 by UV-irradiation.

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