Enhanced photo-degradation of paracetamol on n-platinum-loaded TiO2: The effect of ultrasound and OH/hole scavengers

Ziylan-Yavaş, Asu; Ince, Nilsun H.

doi:10.1016/j.chemosphere.2016.07.090

Cited by 45 publications

(11 citation statements)

References 49 publications

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“…(2) . Hence, it has been a common practice in sonochemistry to monitor the concentration of H 2 O 2 with time to get a fairly accurate idea about the rate of •OH production by ultrasound [51] . Changes in the concentration of H 2 O 2 with time during sonolysis of ultrapure water at 577 kHz is presented in Fig.…”

Section: Resultsmentioning

confidence: 99%

Oxidative decomposition and mineralization of caffeine by advanced oxidation processes: The effect of hybridization

Ziylan-Yavaş

Ince

Ozon

et al. 2021

Ultrasonics Sonochemistry

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The study consists of a detailed investigation of the degradability of the emerging water contaminant-caffeine by homogeneous and heterogeneous Advanced Oxidation Processes (AOP’s), estimation of a synergy index for each hybrid operation thereof, and proposing the most plausible reaction mechanisms that are consistent with the experimental data. It also encompasses evaluation of the effect of the water matrix represented by carbonate species and humic acids, as strong scavengers of hydroxyl radicals. The results showed that single AOP’s such as sonolysis (577 kHz) and photolysis with H 2 O 2 provided complete caffeine elimination, but they were insufficient for the mineralization of the compound. Hybrid AOP’s were considerably more effective, particularly when operated at a heterogeneous mode using commercial TiO 2 . The most effective hybrid process was UV-H 2 O 2 /TiO 2 , which provided more than 75% TOC decay at the minimum test doses of the reagent and catalyst. While the addition of ultrasound to the process significantly increased the rate of caffeine decomposition, it reduced the overall degradation of the compound to 64% in terms of TOC decay. The antagonistic effect was attributed to the formation of excess H 2 O 2 , and the presence of cavity clouds and/or high density layers that inhibited the transmission of UV light. The effect of natural water ingredients was found to reduce the reaction rates, signifying the major contribution of hydroxyl radicals to the destruction of caffeine. The proposed reaction mechanisms based on OH radical attack and the calculated energy barriers were in good agreement with the experimentally detected reaction byproducts.

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Section: Resultsmentioning

confidence: 99%

Oxidative decomposition and mineralization of caffeine by advanced oxidation processes: The effect of hybridization

Ziylan-Yavaş

Ince

Ozon

et al. 2021

Ultrasonics Sonochemistry

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“…The coupling of photocatalysis with sonolysis provides a greater production of hydroxyl radicals in the reaction mixture, an increased mass transfer between the liquid phase and the surface of the catalyst, and excitation of the latter by ultrasonic‐induced luminescence. In addition, ultrasound disaggregates the particles of the catalyst, improving its catalytic activity and, consequently, the surface área 80, 81, 123. The synergy between the two techniques for degradation of pharmaceutical compounds was also observed when employing semiconductors with smaller particle size and/or ultrasound operation at a relatively low frequency 124.…”

Section: Synergistic Effects Of Ultrasound Associated With Other Degradation Technologiesmentioning

confidence: 99%

“…During the process, the simultaneous application of light and ultrasound was considered more effective compared to its sequential or intermittent application and, in addition, the authors observed a synergistic effect with a synergy index of 1.22. A similar system was implemented for the degradation of paracetamol 123. Photocatalysis with ultrasound led to a synergy due to the breakdown of particles and homogenization of active species on the surface of the TiO 2 catalyst loaded by n‐platinum.…”

Section: Synergistic Effects Of Ultrasound Associated With Other Degradation Technologiesmentioning

confidence: 99%

Ultrasound as an Advanced Oxidative Process: A Review on Treating Pharmaceutical Compounds

2021

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Ultrasound treatment, among the various existing water and effluent treatment techniques, is considered an emerging method in recent years due to the degradation of complex organic and inorganic contaminants. It offers substantial advantages, such as cleanliness, safety, and minor or non‐existent secondary pollution products, when compared to other advanced oxidation processes (AOPs). A systematic review of the published peer‐reviewed literature relating the use of ultrasound as an AOP is provided based on theoretical concepts and factors that influence sonochemical reactions. The synergistic effects of ultrasound with other degradation technologies for the oxidation of medications are investigated and the importance of assessing toxicity and biodegradability for the treatment of water and effluents with emerging pollutants is evaluated. The mechanistic understanding of the sonochemical effects in drugs, classification of intermediates, and the development of new treatment technologies are still the subject of future research, however, the synergy of treatments and cavitation studies must be considered.

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“…Potassium iodide (KI) [34,35] was used as the h + and •OH radical scavenger. Sodium nitrate NaNO 3 was used as the e − cb scavenger [36], tert-butyl alcohol (TBA) [37,38] was the •OH scavenger, and p-benzoquinone (pBQ) [39,40] was the O 2…”

Section: The Role Of Reactive Species In the Degradation Mechanismsmentioning

confidence: 99%

Do Gas Nanobubbles Enhance Aqueous Photocatalysis? Experiment and Analysis of Mechanism

Chen

Ateia

et al. 2021

Catalysts

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The performance of photocatalytic advanced oxidation must be improved in order for the technology to make the jump from academic research to widespread use. Research is needed on the factors that cause photocatalysis to become self-limiting. In this study, we introduced, for the first time, nanobubbles continuously into a running photocatalytic reactor. Synthetic air, O2, and N2 bubbles in the size range of 40 to 700 nm were added to a reaction system comprising P25 TiO2 photocatalyst in stirred aqueous solution excited by UV-A lamps, with methyl orange as a target contaminant. The removal of methyl orange was tested under conditions of changing pH and with the addition of different radical scavengers. Results indicated that the oxygen and air nanobubbles improved the photocatalytic degradation of methyl orange—the removal efficiency of methyl orange increased from 58.2 ± 3.5% (N2 aeration) to 71.9 ± 0.6% (O2 aeration). Dissolved oxygen (DO) of 14.93 ± 0.13 mg/L was achieved using O2 nanobubbles in comparison to 8.43 ± 0.34 mg/L without aeration. The photodegradation of methyl orange decreased from 70.8 ± 0.4% to 53.9 ± 0.5% as pH increased from 2 to 10. Experiments using the scavengers showed that O2− was the main reactive species in photocatalytic degradation under highly dissolved oxygen conditions, which also accounted for the observation that the removal efficiency for methyl orange decreased at higher pH. However, without photocatalyst, nanobubbles alone did not improve the removal of methyl orange, and nanobubbles also did not increase the degradation of methyl orange by only photolysis. These experiments show that oxygen and air nanobubbles can act as environmentally friendly catalysts for boosting the performance of photocatalytic water treatment systems.

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Enhanced photo-degradation of paracetamol on n-platinum-loaded TiO2: The effect of ultrasound and OH/hole scavengers

Cited by 45 publications

References 49 publications

Oxidative decomposition and mineralization of caffeine by advanced oxidation processes: The effect of hybridization

Oxidative decomposition and mineralization of caffeine by advanced oxidation processes: The effect of hybridization

Ultrasound as an Advanced Oxidative Process: A Review on Treating Pharmaceutical Compounds

Do Gas Nanobubbles Enhance Aqueous Photocatalysis? Experiment and Analysis of Mechanism

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