Increasing PCB radiolysis rates in transformer oil

Mincher, Bruce J.; Brey, Richard R.; Rodriguez, Rene; Pristupa, Scott; Ruhter, Aaron

doi:10.1016/s0969-806x(02)00361-4

Cited by 28 publications

(18 citation statements)

References 11 publications

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“…The value of decay constant decreased as the CIP concentration increased which means that CIP can be removed at faster rate at lower concentrations, which can also be verified by calculating the radiation dose required for 50% (D 0.5 ) and 90 % (D 0.9 ) removal of CIP as shown in Table 3. These results are similar with the previously reported results [21,22]. fig.…”

Section: Figsupporting

confidence: 94%

Hydroxyl Radical Based Degradation of Ciprofloxacin in Aqueous Solution

Sayed

Shah

Khan

et al. 2016

J. Chil. Chem. Soc.

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This study reports the degradation of ciprofloxacin (CIP) by means of ionizing radiations. Kinetic studies with aqueous concentrations of 4.6, 10, 15, 17.9 mg/L reveals that degradation of CIP follows pseudo-first order kinetics and the decay constant increased with decrease in initial concentration of CIP. The removal efficiency, represented by G-value, decreased with increasing absorbed dose and increased with higher [CIP] 0 concentration at a given absorbed dose. The effects of bubbling CIP solution with N 2 , N 2 O or air on CIP degradation were also studied. The influence of various radical scavengers like tert-butanol, isopropanol, HCO 3 -, CO 3 2-, NO 3 -and NO 2 -as radical scavengers in N 2 -saturated solutions of CIP indicated that • OH were more closely associated with the radiolytic decomposition of CIP than other radicals, such as e -aq or • H. The pH value of aqueous media played a crucial role in the degradation of CIP. It was observed that degradation efficiency was higher under acidic condition compared to degradation in natural or alkaline media. F -, CH 3 COO -and HCOO -were formed as a result of CIP degradation that were analyzed by ion-chromatography.

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Section: Figsupporting

confidence: 94%

Hydroxyl Radical Based Degradation of Ciprofloxacin in Aqueous Solution

Sayed

Shah

Khan

et al. 2016

J. Chil. Chem. Soc.

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“…Table 3 shows that the decay constant decreased at higher concentration of CIP and as a result higher doses are required for 50 % or 90 % degradation of CIP. These observations are consistent with the previously reported results for decomposition of 2, 4, 6 -trinitrotoluene by gamma irradiation and PCBs decomposition by radiolysis [38,39]. A c c e p t e d M a n u s c r i p t 15 chloroform [31].…”

Section: Kinetics Study For the Radiolytic Degradation Of Cipsupporting

confidence: 92%

Degradation of ciprofloxacin in water by advanced oxidation process: kinetics study, influencing parameters and degradation pathways

Sayed

Ismail

Khan

et al. 2015

Environmental Technology

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Gamma-radiation-induced degradation of ciprofloxacin (CIP) in aqueous solution and the factors affecting the degradation process have been investigated. The results showed that CIP (4.6 mg/L) was almost completely degraded at an absorbed dose of 870 Gy. The kinetic studies of aqueous solutions containing 4.6, 10, 15 and 17.9 mg/L indicated that the decomposition of CIP by gamma irradiation followed pseudo-first-order kinetics and the decay constant (k) decreased from 5.9 × 10(-3) to 1.6 × 10(-3) Gy(-1) with an increase in CIP initial concentration from 4.6 to 17.9 mg/L. The effect of saturation of CIP solution with N2, N2O or air on radiation-induced degradation of CIP was also investigated. The effects of radical scavengers, such as t-BuOH and i-PrOH, showed the role of reactive radicals towards degradation of CIP in the order of OH > e(aq)- . H. The apparent second-order rate constant of [Formula: see text] with CIP was calculated to be 2.64 × 10(9) M(-1) s(-1). The effects of solution pH as well as natural water contaminants, such as [HCO3-, CO3(2-), and NO2-, on CIP degradation by gamma-irradiation were also investigated. Major degradation products, including organic acids, were identified using UPLC-MS/MS and IC, and degradation pathways have been proposed.

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“…However, at initial concentrations of 23.6 and 40.2 mg/L, the rate constants were 2.778 and 2.174 kGy -1 , respectively. These results are consistent with published findings for radiolytic degradation of individual polychlorinated biphenyl (PCB) congeners (Mincher et al, 2002).…”

Section: Influence Of Operational Parameters On the Naproxen Degradationsupporting

confidence: 92%

Degradation Kinetics and By-Products of Naproxen in Aqueous Solutions by Gamma Irradiation

Zheng

Zhang

et al. 2012

Environmental Engineering Science

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This study focused on the degradation of the emerging contaminant naproxen in aqueous solutions by gamma irradiation. Influence of initial naproxen concentration, solution pH, various additives (CH 3 OH, H 2 O 2 , NO À 3 , and humic acid), and absorbed dose on naproxen degradation were investigated. At a naproxen concentration of 23.6 mg/L and an absorbed dose of 1.0 kGy, the extent of naproxen degradation was 98%. The degradation reaction of naproxen followed first-order like kinetics. Addition of 40 mg/L humic acid or 0.5% H 2 O 2 enhanced the naproxen degradation, whereas 1.5% CH 3 OH and 1.5% H 2 O 2 inhibited naproxen degradation. Added NO À 3 slightly decreased naproxen degradation. The naproxen degradation efficiency was higher under acidic conditions than in neutral or alkaline media. The solution pH value became lower as the absorbed dose increased. Identification of byproducts revealed that decarboxylation is the principal initial process in the degradation of naproxen under the conditions used in these experiments.

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Increasing PCB radiolysis rates in transformer oil

Cited by 28 publications

References 11 publications

Hydroxyl Radical Based Degradation of Ciprofloxacin in Aqueous Solution

Hydroxyl Radical Based Degradation of Ciprofloxacin in Aqueous Solution

Degradation of ciprofloxacin in water by advanced oxidation process: kinetics study, influencing parameters and degradation pathways

Degradation Kinetics and By-Products of Naproxen in Aqueous Solutions by Gamma Irradiation

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