Kinetics of the sulfate radical-mediated photo-oxidation of humic substances

A self-designed reaction device was used as a promising equipment to investigate the oxidation characteristics and kinetics of rosin pentaerythritol ester (RPE) under UV irradiation. Photo-oxidation kinetics and the initial quantum yield (Φ) of RPE were calculated. The initial oxidation product of the photo-oxidation reaction—peroxide was analyzed by iodimetry. The peroxide concentration is related to the light intensity (I) and the temperature (T), and the increasing T and I would destabilize the RPE by accelerating peroxide forming. Photo-oxidation of RPE follows the pseudo first-order reaction kinetics. The relationship between activation energy and logarithm of light intensity (ln I) is linear, and it is expressed as Ea = −4.937ln I + 45.565. Φ was calculated by the photo-oxidation kinetics, and the average value of Φ was 7.19% in the light intensity range of 200–800 μW cm−2. This research can provide fundamental information for application of RPE, and help obtain a better understanding of the stability of rosin esters.

Download Full-text

Photo-oxidation and Kinetics of Gaseous Elemental Mercury Using CeO 2/TiO 2{001} and {101} Photocatalysts in the Atmosphere of Multiple Air Pollutants

SSRN Electronic Journal ◽

10.2139/ssrn.3979450 ◽

2021 ◽

Author(s):

Chung-Shin Yuan ◽

Ching-Hsun Shih ◽

Iau-Ren Ie ◽

Ji-Ren Zheng ◽

Zu-Bei Lin

Keyword(s):

Air Pollutants ◽

Elemental Mercury ◽

Gaseous Elemental Mercury ◽

Photo Oxidation ◽

Kinetics Of

Download Full-text

Photo Oxidation Reaction Kinetics of Ethyl Propionate with Cl Atom and Formation of Propionic Acid

The Journal of Physical Chemistry A ◽

10.1021/acs.jpca.8b05215 ◽

2018 ◽

Vol 122 (42) ◽

pp. 8274-8285 ◽

Cited By ~ 7

Author(s):

Ramya Cheramangalath Balan ◽

B. Rajakumar

Keyword(s):

Reaction Kinetics ◽

Propionic Acid ◽

Oxidation Reaction ◽

Ethyl Propionate ◽

Photo Oxidation ◽

Kinetics Of ◽

Cl Atom

Download Full-text

Enhancement of carboxylic acid degradation with sulfate radical generated by persulfate activation

Water Science & Technology ◽

10.2166/wst.2010.008 ◽

2010 ◽

Vol 61 (5) ◽

pp. 1221-1226 ◽

Cited By ~ 9

Author(s):

J. Criquet ◽

P. Nebout ◽

N. Karpel Vel Leitner

Keyword(s):

Aqueous Solution ◽

Citric Acid ◽

Carboxylic Acids ◽

Sulfate Radical ◽

Acid Degradation ◽

Competitive Reactions ◽

Radical Production ◽

Persulfate Activation ◽

Kinetics Of

The aim of this work was to investigate the generation of sulfate radical for the removal of two carboxylic acids in aqueous solution: acetic and citric acids. From photochemical and radiolytic processes, kinetics of the degradation of these two carboxylic acids was studied as a function of the pH of the solution. It was shown that the maximum of acetic acid degradation occurred at pH 5. Above this pH, competitive reactions with the carbon mineralized inhibit the reaction of with the solute. In the case of citric acid, pH has only a little effect on the kinetic of citric acid degradation. The determination of mineralization yields shows several differences depending on carboxylic acids and pH. The degradation of both carboxylic acids was also studied in the radiolysis process whether with or without persulfate addition. A comparison of the processes of sulfate radical production is presented.

Download Full-text