Computer simulation of chemical reactions occurring in collapsing acoustical bubble: dependence of free radicals production on operational conditions

Merouani, Slimane; Hamdaoui, Oualid; Rezgui, Yacine; Guemini, Miloud

doi:10.1007/s11164-013-1240-y

Cited by 71 publications

(38 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A detailed quantitative numerical analysis of the effect of acoustic amplitude on the single bubble yield, i.e. • OH production, is available in our previous paper [52]. With increase in acoustic amplitude, the expansion ratio of the cavity R max /R 0 increases (R max is the maximum bubble radius and R 0 is the initial bubble radius), leading to more water vapor being trapped inside the cavity at the collapse.…”

Section: Effect Of Acoustic Intensitymentioning

confidence: 99%

Sonochemical degradation of naphthol blue black in water: Effect of operating parameters

Ferkous

Hamdaoui

Merouani

2015

Ultrasonics Sonochemistry

Self Cite

View full text Add to dashboard Cite

In this work, the sonochemical degradation of naphthol blue black (NBB), an acidic diazo dye, in water was investigated. The effects of several operating parameters such as initial NBB concentration, acoustic intensity, ultrasonic frequency, nature of the dissolved gas and solution pH on the degradation of the dye were carried out. The obtained results showed that ultrasound completely destroyed NBB (5 mg L(-1)) after 45 min of sonication and most of the chemical oxygen demand was eliminated after 90 min of treatment. It was found that the initial rate of sonolytic degradation increased with increasing the initial NBB concentration. The fitting of the experimental data by a heterogeneous Langmuir-kinetics model showed that NBB degraded mainly at the interfacial region of the bubble by hydroxyl radical (OH) attack. The degradation rate of the dye increased substantially with increasing acoustic intensity in the range of 0.44-3.58 W cm(-2) and decreased with increasing frequency in the range of 585-1140 kHz. The rate of NBB degradation decreased in the order of Ar>air>N2. The significant degradation was achieved in acidic conditions (pH 2) where the initial degradation rate was 1.37 and 1.66 higher than those observed at pH 6 and pH 10, respectively.

show abstract

Section: Effect Of Acoustic Intensitymentioning

confidence: 99%

Sonochemical degradation of naphthol blue black in water: Effect of operating parameters

Ferkous

Hamdaoui

Merouani

2015

Ultrasonics Sonochemistry

Self Cite

View full text Add to dashboard Cite

show abstract

“…7 in Ref. [54]). This can promote the formation of free radicals coming from the dissociation of water vapor molecules.…”

Section: Single Bubble Yield Dependence Of Liquid Temperaturementioning

confidence: 91%

“…It was seen that the production of Å OH increases as the liquid bulk temperature increases from 25 to 35°C and then decreases with further increase in the bulk liquid temperature. An interesting discussion about the existence of an optimum bulk liquid temperature for the production of Å OH inside a single bubble have been made elsewhere [54]. In short, the trend was resulted from the competition between two important parameters: the amount of water vapor trapped in the bubble at the collapse and the maximum bubble temperature achieved at the end of the bubble collapse.…”

Section: Single Bubble Yield Dependence Of Liquid Temperaturementioning

confidence: 99%

“…This can promote the formation of free radicals coming from the dissociation of water vapor molecules. But increasing liquid temperature simultaneously involves less violent collapse (decreasing c of the gas mixture) leading to lower internal bubble temperature at the end of the bubble collapse [54], which reduces the decomposition of molecules into free radicals. These two competing effects conduct to an optimum bulk liquid temperature for the production of Å OH as shown in Fig.…”

Section: Single Bubble Yield Dependence Of Liquid Temperaturementioning

confidence: 99%

See 1 more Smart Citation

Experimental and numerical investigation of the effect of liquid temperature on the sonolytic degradation of some organic dyes in water

Merouani

Hamdaoui

Boutamine

et al. 2016

Ultrasonics Sonochemistry

Self Cite

View full text Add to dashboard Cite

This paper presents a comprehensive experimental and numerical investigation of the effects of liquid temperature on the sonochemical degradation of three organic dyes, Rhodamine B (RhB), Acid orange 7 (AO7) and Malachite green (MG), largely used in the textile industry. The experiments have been carried out for an ultrasonic frequency of 300 kHz. The obtained experimental results were discussed using a new approach combining the results of single-bubble event and the number of active bubbles. The single-bubble event was predicted using a model that combines the bubble dynamics with chemical kinetics occurring inside a bubble during the strong collapse. The number of active bubbles was predicted using a method developed in our previous work. The experiments showed that the degradation rate of the three dyes increased significantly with increasing liquid temperature in the range 25-55°C. It was predicted that the main pathway of pollutants degradation is the attack by OH radicals. The simulations showed that there exists an optimum liquid temperature of about 35°C for the production of OH inside a bubble whereas the number of active bubbles increased sharply with the rise of the liquid temperature. It was predicted that the overall production rate of OH increased with increasing liquid temperature in the range 25-55°C. Finally, it was concluded that the effect of liquid temperature on the sonochemical degradation of the three dyes in aqueous phase was controlled by the number of active bubbles in the range 35-55°C and by both the number of bubbles and the single bubble yield in the range 25-35°C.

show abstract

“…With an increase in acoustic amplitude, the bubble will reach higher R max and lower R min with a higher amount of water vapor being trapped in the bubble at the collapse (R max and R min are, respectively, the maximum and the minimum bubble radii attained during oscillation). 49 This results in stronger implosions with higher bubble core temperatures and pressures at the final stage of the bubble collapse, and with the higher water vapor trapped at this moment, higher amounts of hydroxyl radical will be generated since it results principally from the dissociation of water vapor molecules inside the bubble. Moreover, it has recently been reported that the acoustic amplitude affects the range of ambient bubble radius for the production of HO • radical and the higher the acoustic amplitude was, the higher was the range of active bubbles for the production of the oxidants.…”

Section: Effect Of Power Intensitymentioning

confidence: 99%

Sonochemical degradation of Basic Red 29 in aqueous media

Boutamine¹,

Merouani²,

Hamdaoui³

2017

Turk J Chem

Self Cite

View full text Add to dashboard Cite

Abstract:In this work, the degradation of Basic Red 29 (BR29), an azo dye, was investigated using a high-frequency ultrasonic reactor (300 kHz). The influence of several parameters such as initial substrate concentration (5-200 mg L −1 ) , pH (3-10.1), ultrasonic power (20-80 W), and nature of the dissolved gas (Ar, air, and N 2) on the degradation of BR29was assessed. Additionally, the impact of natural matrices (seawater and natural and river waters) on the degradation rate of BR29 was clarified. Degradation experiments with radical scavengers, tert-butyl alcohol and glucose, showed that BR29 degraded mainly through HO• radical attack at the gas/liquid interface of the cavitation bubbles. The degradation of the dye was strongly sensitive to the operational conditions. The natural matrices enhanced the degradation of the dye. Ultrasonic mineralization and oxidation of the dye solution was significantly enhanced by addition of a low quantity of Fe 2+ (15 mg L −1 ) .

show abstract

Computer simulation of chemical reactions occurring in collapsing acoustical bubble: dependence of free radicals production on operational conditions

Cited by 71 publications

References 40 publications

Sonochemical degradation of naphthol blue black in water: Effect of operating parameters

Sonochemical degradation of naphthol blue black in water: Effect of operating parameters

Experimental and numerical investigation of the effect of liquid temperature on the sonolytic degradation of some organic dyes in water

Sonochemical degradation of Basic Red 29 in aqueous media

Contact Info

Product

Resources

About