scholarly journals Effects of Antioxidants and Additional Emulsifiers on the Stability of Emulsified Milk Fat in the Photo/Radical Oxidation System

2014 ◽  
Vol 63 (9) ◽  
pp. 893-901
Author(s):  
Yukihiro Yamamoto ◽  
Shinichiro Hiyama ◽  
Yoshihiko Takase ◽  
Akio Kadowaki ◽  
Setsuko Hara
Keyword(s):  
Milk Fat ◽  
Radical Oxidation ◽  
The Stability ◽  
Oxidation System

scholarly journals Performance of PES/LSMM-OGCN Photocatalytic Membrane for Phenol Removal: Effect of OGCN Loading

Membranes ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 42 ◽  
Author(s):  
Noor Salim ◽  
Nor Nor ◽  
Juhana Jaafar ◽  
Ahmad Ismail ◽  
Takeshi Matsuura ◽  
...  
Keyword(s):  
Phase Inversion ◽  
Photocatalytic Oxidation ◽  
Photocatalytic Performance ◽  
Phenol Degradation ◽  
Phenol Removal ◽  
Membrane Performance ◽  
Phase Inversion Technique ◽  
The Stability ◽  
Oxidation System ◽  
Catalyst Distribution

In designing a photocatalytic oxidation system, the immobilized photocatalyst technique becomes highly profitable due to its promising capability in treating organic pollutants such as phenols in wastewater. In this study, hydrophiLic surface modifying macromolecules (LSMM) modified polyethersulfone (PES) hybrid photocatalytic membranes incorporated with oxygenated graphitic carbon nitride (OGCN) was successfully developed using phase inversion technique. The effectiveness of the hybrid photocatalytic membrane was determined under different loading of OGCN photocatalyst (0, 0.5, 1.0, 1.5, 2.0, and 2.5 wt%). The best amount of OGCN in the casting solution was 1.0 wt% as the agglomeration did not occur considering the stability of the membrane performance and morphology. The highest flux of 264 L/m2·h was achieved by PES/LSMM-OGCN1.5wt% membrane. However, the highest flux performance was not an advantage in this situation as the flux reduced the rejection value due to open pores. The membrane with the highest photocatalytic performance was obtained at 1.0 wt% of OGCN loading with 35.78% phenol degradation after 6 h. Regardless of the lower rejection value, the performance shown by the PES/LSMM-OGCN1.0wt% membrane was still competent because of the small difference of less than 1% to that of the PES/LSMM-OGCN0wt% membrane. Based on the findings, it can be concluded that the optimisation of the OGCN loading in the PES hybrid photocatalytic membrane indeed plays an important role towards enhancing the catalyst distribution, phenol degradation, and acceptable rejection above all considerations.

Congo Red Degradation in Anode and Sunlight/derivative Persulfate Composite Oxidation System

2012 ◽  
Vol 15 (1) ◽  
Author(s):  
Naidong Zhang ◽  
Zhengjiang Zhu ◽  
Wanli Luan
Keyword(s):  
Organic Compounds ◽  
Anodic Oxidation ◽  
Congo Red ◽  
Radical Oxidation ◽  
Degradation Reaction ◽  
Oxidation System ◽  
Refractory Organics

AbstractAnodic oxidation and sulphate radical oxidation were combined in the study for degradation of refractory organics. The degradation reaction of organic compounds and persulfate generation reaction occur simultaneously in Pt anodic oxidation system with electrolyte of Na

Light-induced Free Radical Oxidation of 2-Oxo-1,2,3,4-tetrahydropyrimidines

2012 ◽  
Vol 67 (3) ◽  
pp. 263-268
Author(s):  
Hamid Reza Memarian ◽  
Leila Hejazi ◽  
Asadallah Farhadi
Keyword(s):  
Benzoyl Peroxide ◽  
Free Radical Oxidation ◽  
Phenyl Group ◽  
Heterocyclic Ring ◽  
Radical Intermediate ◽  
Radical Oxidation ◽  
Photo Oxidation ◽  
Rate Determining Step ◽  
The Stability ◽  
Allylic Radical

A variety of 4-substituted 5-acetyl- and 5-carboethoxy-2-oxo-1,2,3,4-tetrahydropyrimidines were oxidized under UV irradiation in the presence or absence of benzoyl peroxide. The nature of the substituents on the 4- and 5-positions of the heterocyclic ring affects the rate of photo-oxidation, and irradiation of these compounds in the presence of benzoyl peroxide decreases the time of reaction drastically. Removal of 4-H by a benzoyloxy radical under formation of a trihydropyrimidinoyl radical intermediate occurs in the rate-determining step. The stability of this benzylic and allylic radical intermediate is affected by the nature and the position of the additional substituent on the phenyl group located at C-4.

scholarly journals Chemical composition and hydrolysis of organic nitrate aerosol formed from hydroxyl and nitrate radical oxidation of <i>α</i>-pinene and <i>β</i>-pinene

2019 ◽  
Vol 19 (19) ◽  
pp. 12749-12766 ◽  
Author(s):  
Masayuki Takeuchi ◽  
Nga L. Ng
Keyword(s):  
Chemical Composition ◽  
Life Cycles ◽  
Bulk Solution ◽  
Organic Nitrate ◽  
Loss Mechanism ◽  
Radical Oxidation ◽  
Hydrolysis Process ◽  
Chamber Studies ◽  
Hydrolysis Of ◽  
Oxidation System

Abstract. Atmospheric organic nitrate (ON) is thought to play a crucial role in the formation potential of ozone and aerosol, which are the leading air pollutants of concern across the world. Limited fundamental knowledge and understanding of the life cycles of ON currently hinder the ability to quantitatively assess its impacts on the formation of these pollutants. Although hydrolysis is currently considered an important loss mechanism of ON based on prior field measurement studies, this process for atmospherically relevant ON has not been well constrained by fundamental laboratory studies. In this comprehensive study, we investigated the chemical composition and hydrolysis process of particulate ON (pON) formed from the oxidation of α-pinene and β-pinene by hydroxyl (OH⚫) and nitrate radicals (NO3⚫). For pON that undergoes hydrolysis, the hydrolysis lifetime is determined to be no more than 30 min for all systems explored. This is significantly shorter than those reported in previous chamber studies (i.e., 3–6 h) but is consistent with the reported lifetime from bulk solution measurement studies (i.e., 0.02–8.8 h). The discrepancy appears to stem from the choice of proxy used to estimate the hydrolysis lifetime. The measured hydrolyzable fractions of pON (FH) in the α-pinene + OH⚫, β-pinene + OH⚫, α-pinene + NO3⚫, and β-pinene + NO3⚫ systems are 23 %–32 %, 27 %–34 %, 9 %–17 %, and 9 %–15 %, respectively. While a very low FH for the NO3⚫ oxidation system is expected based on prior studies, FH for the OH⚫ oxidation system is surprisingly lower than predicted in past studies. Overall, the hydrolysis lifetime as well as FH obtained in this study serve as experimentally constrained parameters that are required in regional and global chemical transport models to accurately evaluate the impacts of ON on nitrogen budget and formation of ozone and aerosol.

The stability of covalently immobilization of TEMPO on the polymer surface through ionic liquid linkage: a comparative and model research

e-Polymers ◽  
2015 ◽  
Vol 15 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Danjie Li ◽  
Xianbo Shen ◽  
Liang Chen ◽  
Huanchang Jiang ◽  
Jianli Wang
Keyword(s):  
Ionic Liquid ◽  
Active Sites ◽  
Polymer Surface ◽  
Nitrogen Atmosphere ◽  
Significant Loss ◽  
Thermal Stabilities ◽  
Additional Advantage ◽  
Model Research ◽  
The Stability ◽  
Oxidation System

AbstractCovalently immobilizing the active sites or ligands on a polymer surface is an efficient strategy to achieve a full use of expensive organic parts. In this work, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) was anchored onto polystyrene beads through an ether bond or an ionic liquid bridge. We quantitatively compared their thermal stabilities at nitrogen atmosphere and their chemical stabilities in a biphasic oxidation surrounding. It was found that the ionic liquid-bridged TEMPO exhibited an additional advantage of stability and could be reused for 30 consecutive recycles with a conversion ratio above 90% without any significant loss under the condition of the Montanari oxidation system (NaClO/NaBr, CH2Cl2/water), and the overall reaction time exceeded 2700 min.

Effect of Milk Fat on the Stability of Vitamin A in UHT Milk

1986 ◽  
Vol 19 (4) ◽  
pp. xxxvii
Author(s):  
Betty L.T. Lau ◽  
Y. Kakuda ◽  
D.R. Arnott
Keyword(s):  
Vitamin A ◽  
Milk Fat ◽  
Uht Milk ◽  
The Stability
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