Measurement of chemical activity of ultrasonic cavitation in aqueous solutions

Todd, Janet

doi:10.1016/0041-624x(70)91041-3

Cited by 26 publications

(8 citation statements)

References 10 publications

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“…Todd (23) has shown that a value of U(Fe3+)02 = 3.9 + 0.1, where U is defined as the number of molecules or radicals reacting per lOOeV of chemico-acoustic energy, may be applicable to cavitation. From the chemical dosimeter results and using this value of U, the chemico-acoustic energy absorbed was calculated to be 11 700 rad min-I for the insonation conditions employed in this work.…”

Section: Resultsmentioning

confidence: 99%

The effect of ultrasound on water in the presence of dissolved gases

Mead¹,

Sutherland²,

Verrall³

1976

Can. J. Chem.

148

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Sonolysis of water at 447 kHz causes a decrease in the pH. The products formed depend to some extent on the nature of the dissolved gases; products observed are hydrogen peroxide, nitrous and nitric acid. The yield of hydrogen peroxide follows the order O2 > air > Ar > N2. In the case of total acid (nitrous and nitric) the yield follows the order air >N2 > Ar > O2. Nitrogen fixation occurs in the presence of Ar and O2 because of the presence of small amounts of N2 either as an impurity in the dissolved gases, or as residual air in the incompletely degassed water.An attempt was made by using the Fricke dosimeter to obtain information on the relative chemical activity of cavitation.

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Section: Resultsmentioning

confidence: 99%

The effect of ultrasound on water in the presence of dissolved gases

Mead¹,

Sutherland²,

Verrall³

1976

Can. J. Chem.

148

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“…The presence of • OH is also indicated by the hydroxylation of aqueous benzoic acid (38) and terephthalic acid (28,39) during sonication. The G-value (molecules produced per 100 eV or 1.6 × 10 -17 J) for the formation of • OH during sonolysis has been estimated to be 0.35 by using the Fricke dosimeter (40).…”

Section: Aqueous Cavitation Chemistrymentioning

confidence: 99%

Optimization of Ultrasonic Irradiation as an Advanced Oxidation Technology

Hua

Hoffmann

1997

Environ. Sci. Technol.

424

244

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The optimization of ultrasonic irradiation as an advanced oxidation technology can be achieved by adjusting the ultrasonic frequency and saturating gas during sonolysis. The sonolytic production of hydrogen peroxide (H 2 O 2 ) and hydroxyl radical ( • OH) has been investigated at the ultrasonic frequencies of 20, 40, 80, and 500 kHz, respectively, in the presence of four different saturating gases (i.e., Kr, Ar, He, O 2 ) at each frequency. H 2 O 2 was measured with a KI dosimeter, and the formation of • OH was monitored by trapping with terephthalic acid. Both the applied frequency and the physicochemical properties of the saturating gases influence the sonochemical rates of production of • OH and H 2 O 2 . At 20 kHz, the rate contants for the production of H 2 O 2 vary over an order of magnitude as a function of the nature of the dissolved gas (0.0508 and 1.31 µM min -1 ). Similar trends are observed for the production of • OH at the same frequencies and under an identical set of saturating gases. The highest rates of production of H 2 O 2 (pH 7, 2.94 µM min -1 ) and • OH (pH 11, 0.391 µM min -1 ) are observed during sonolysis of Kr-saturated solutions at 500 kHz. Sonolysis of He-saturated solutions at 20 kHz results in the lowest rates of production of H 2 O 2 (0.0508 µM min -1 ) and • OH (0.0310 µM min -1 ). Decreasing differences among the saturating gases at higher frequencies are attributed to changes in bubble dynamics and thermodynamics as the resonant bubble radius decreases from 177 µm at 20 kHz to 7 µm at 500 kHz.

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“…[4] Chemical approaches rely on the extreme conditions generated to drive various reactions, after which reaction product is quantified in various dosimeters. The Fricke dosimeter [5][6][7][8] measures Fe 2+ oxidation to Fe 3+ . The terephthalate dosimeter, developed previously for measuring radiation, uses fluorescence to measure the 2-hydroxyterephthlate generated from starting terephthalate.…”

Section: Introductionmentioning

confidence: 99%

Chloral hydrate as an accelerant for the Weissler reaction

Pan

Chen

2021

J Chinese Chemical Soc

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The Weissler reaction, in which a potassium iodide aqueous solution is oxidized to produce triiodide ion, is a conventional means of quantifying ultrasoundinduced inertial cavitation. The reaction is commonly accelerated by saturating the solution with carbon tetrachloride, thereby increasing triiodide ion yields for any given ultrasound exposure. Chloral hydrate, being less toxic and easier to handle, is an alternative accelerant that was characterized. Observed triiodide ion levels were around 11-15% of that produced with carbon tetrachloride. Chloral hydrate was shown to be less susceptible to accelerant exhaustion for prolonged measurements. Spectrophotometric measurement of triiodide ion is typically performed through absorbance measurements at 350 nm; however, there is a separate absorption peak at 288 nm. Measurements at 288 nm were strongly correlated with 350 nm measurements. Due to the greater molar absorptivity at 288 nm, Weissler reaction measurements in the future may be preferably conducted at this alternative wavelength regardless of the means of acceleration.

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Measurement of chemical activity of ultrasonic cavitation in aqueous solutions

Cited by 26 publications

References 10 publications

The effect of ultrasound on water in the presence of dissolved gases

The effect of ultrasound on water in the presence of dissolved gases

Optimization of Ultrasonic Irradiation as an Advanced Oxidation Technology

Chloral hydrate as an accelerant for the Weissler reaction

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