Gamma radiation-induced degradation of p-nitrophenol (PNP) in the presence of hydrogen peroxide (H2O2) in aqueous solution

2010 ◽  
Vol 177 (1-3) ◽  
pp. 1061-1067 ◽  
Author(s):  
Shaoqing Yu ◽  
Jun Hu ◽  
Jianlong Wang

The radiolysis of dilute aqueous solutions containing ethylene and oxygen has been investigated. Pulse radiolysis was used to measure the rate constants for the addition of hydroxyl radicals to ethylene, the binary decomposition of the resulting hydroxyethyl radicals and their addition to ethylene and reaction with oxygen to yield peroxy radicals. The rate constants have also been determined for the mutual interaction of the peroxy radicals and their reaction with ferrous ions. The principal products of γ -irradiation were aldehydes and organic hydroperoxides. Hydrogen peroxide was found in yields close to the molecular yield from water. The polymer produced in the absence of oxygen was not formed, and glycollaldehyde, reported as a major product by previous workers, could not be detected. At constant composition of the gas mixtures, product yields were unaffected by total pressure in the range up to 40 atm, but were strongly dependent on the proportion of oxygen. Aldehyde yields were markedly greater at pH 1.2 than in neutral solution. The influence of ferrous ions an d of added hydrogen peroxide has been determined. The pulse radiolysis and γ -irradiation experiments complement one another and show that the radiation-induced oxidation of ethylene in aqueous solution involves the same primary reactions as occur in the absence of oxygen, followed by the formation and further reactions of peroxy radicals.


1970 ◽  
Vol 48 (8) ◽  
pp. 1232-1238 ◽  
Author(s):  
C. E. Burchill ◽  
I. S. Ginns

The radiation-induced oxidation of 2-propanol by hydrogen peroxide in neutral deaerated aqueous solution has been investigated. 2-Propanol is oxidized to acetone, and hydrogen peroxide reduced in stoichiometrically equivalent high yields. The yields are independent of hydrogen peroxide concentration in the range 5 × 10−2 to 10−3 M and linearly dependent on alcohol concentration in the range 0.13 to 1.05 M. The reaction yields increased with decreasing dose rate.The results are explained by a chain mechanism in which initiation occurs via H-atom abstraction from 2-propanol to form either (CH3)2ĊOH (1) or CH3 CHOH ĊH2 (2). 1 reacts with H2O2 in a chain propagating reaction[Formula: see text]2 may abstract the α hydrogen from the parent alcohol[Formula: see text]or undergo bimolecular termination. A lower limit of 53 ± 101mole−1 s−1 is estimated for the rate constant for this radical conversion reaction.


Chemosphere ◽  
2018 ◽  
Vol 208 ◽  
pp. 606-613 ◽  
Author(s):  
Rahil Changotra ◽  
Jhimli Paul Guin ◽  
Lalit Varshney ◽  
Amit Dhir

2020 ◽  
Vol 168 ◽  
pp. 108637 ◽  
Author(s):  
Rabia Arshad ◽  
Tanveer H. Bokhari ◽  
Kaleem K. Khosa ◽  
Ijaz A. Bhatti ◽  
Majid Munir ◽  
...  

1970 ◽  
Vol 48 (16) ◽  
pp. 2628-2632 ◽  
Author(s):  
C. E. Burchill ◽  
I. S. Ginns

The radiation-induced chain oxidation of ethanol and methanol by hydrogen peroxide in deaerated aqueous solutions has been investigated. In each case the alcohol is oxidized to the corresponding aldehyde and hydrogen peroxide is reduced in equivalent yield. With ethanol as the oxidizable substrate the yields are independent of peroxide concentration in the range 5 × 10−2 to 5 × 10−3 M and linearly dependent on ethanol concentration in the range 0.085 to 0.85 M. In contrast, the oxidation of methanol is first order in hydrogen peroxide, independent of methanol concentration up to 2.0 M and shows a simple square root dependence on dose rate. The differences are explained by consideration of the participation of two different radicals derived from ethanol, CH3ĊHOH and ĊH2CH2OH, whereas only one radical, ĊH2OH, is formed from methanol.


Author(s):  
Xiaoyan Wang ◽  
Jinmei Du ◽  
Changhai Xu

Abstract:: Activated peroxide systems are formed by adding so-called bleach activators to aqueous solution of hydrogen peroxide, developed in the seventies of the last century for use in domestic laundry for their high energy efficiency and introduced at the beginning of the 21st century to the textile industry as an approach toward overcoming the extensive energy consumption in bleaching. In activated peroxide systems, bleach activators undergo perhydrolysis to generate more kinetically active peracids that enable bleaching under milder conditions while hydrolysis of bleach activators and decomposition of peracids may occur as side reactions to weaken the bleaching efficiency. This mini-review aims to summarize these competitive reactions in activated peroxide systems and their influence on bleaching performance.


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