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Fattahi K, Boffito DC, Robert E. Quantifying the chemical activity of cavitation bubbles in a cluster. Sci Rep 2024; 14:7978. [PMID: 38575603 PMCID: PMC10994948 DOI: 10.1038/s41598-024-56906-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 03/12/2024] [Indexed: 04/06/2024] Open
Abstract
Acoustic cavitation bubbles drive chemical processes through their dynamic lifecycle in liquids. These bubbles are abundant within sonoreactors, where their behavior becomes complex within clusters. This study quantifies their chemical effects within well-defined clusters using a new laser-based method. We focus a laser beam into water, inducing a breakdown that generates a single cavitation bubble. This bubble undergoes multiple collapses, releasing several shockwaves. These shockwaves propagate into the surrounding medium, leading to the formation of secondary bubbles near a reflector, separated from the input laser beam. We evaluate the chemical activity of these bubble clusters of various sizes by KI dosimetry, and to gain insights into their dynamics, we employ high-speed imaging. Hydrophone measurements show that conversion from focused shockwave energy to chemical reactions increases to a maximum of 16.5%. Additional increases in shockwave energy result in denser bubble clusters and a slightly decreased conversion rate, falling to 14.9%, highlighting the key role of bubble dynamics in the transformation of mechanical to chemical energy and as a result in the efficiency of the sonoreactors. The size and frequency of bubble collapses influence the cluster's chemical reactivity. We introduce a correlation for predicting the conversion rate of cluster energy to chemical energy, based on the cluster's energy density. The maximum conversion rate occurs at a cluster energy density of 2500 J/L, linked to a cluster with an average bubble diameter of 91 μ m, a bubble density of 3500 bubbles/ml, and a bubble-to-bubble distance ratio of 8.
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Affiliation(s)
- Kobra Fattahi
- Department of Chemical Engineering, Polytechnique Montréal, C.P. 6079, Succ. CV, Montreal, QC, H3C 3A7, Canada
| | - Daria C Boffito
- Department of Chemical Engineering, Polytechnique Montréal, C.P. 6079, Succ. CV, Montreal, QC, H3C 3A7, Canada
| | - Etienne Robert
- Department of Mechanical Engineering, Polytechnique Montréal, C.P. 6079, Succ. CV, Montreal, QC, H3C 3A7, Canada.
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2
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Su K, Li B, Wu J, Xin P, Qian S. Joint effects of gas bubbles and solid particles on sonochemical inhibition in sonicated aqueous solutions. ULTRASONICS SONOCHEMISTRY 2023; 101:106717. [PMID: 38086127 PMCID: PMC10726247 DOI: 10.1016/j.ultsonch.2023.106717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 12/02/2023] [Accepted: 12/05/2023] [Indexed: 12/21/2023]
Abstract
Wastewater is a multicomponent and multiphase mixture. Gas bubbles and solid particles in the dispersed phase influence sonochemical efficiency during ultrasonic treatment of wastewater, sometimes unfavorably; however, the influencing factors and mechanisms remain unclear. In this paper, the influence of argon gas bubbles (1.2 mm) and monodisperse silica particles (0.1 mm) on sonochemical effects in an aqueous system using a horn-type reactor (20 kHz) is reported. Triiodide formation decreased with an increase in the volume fraction of either or both phases. The two phases started inhibiting sonoreactions as the total volume fraction approached 3.0-4.0 vol% compared to pure water. The effect of the gas-to-solid ratio is also considered. We propose an acoustic attenuation model, which incorporates the scattering effect of solid particles and the thermal effect of gas bubbles. The agreement between the modeling and experimental results demonstrates that the two phases are jointly responsible for sonochemical inhibition by increasing ultrasound attenuation. This enhances the understanding of sonochemistry in gas-solid-liquid systems and helps regulate gases and solids in sonochemical reactors.
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Affiliation(s)
- Kunpeng Su
- College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, China; State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China
| | - Binghui Li
- College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, China
| | - Jianhua Wu
- College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, China.
| | - Pei Xin
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China; Yangtze Institute for Conservation and Development, Hohai University, Nanjing 210098, China
| | - Shangtuo Qian
- College of Agricultural Science and Engineering, Hohai University, Nanjing 210098, China
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3
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Lee S, Son Y. Effects of gas saturation and sparging on sonochemical oxidation activity under different liquid level and volume conditions in 300-kHz sonoreactors: Zeroth- and first-order reaction comparison using KI dosimetry and BPA degradation. ULTRASONICS SONOCHEMISTRY 2023; 98:106521. [PMID: 37473616 PMCID: PMC10371822 DOI: 10.1016/j.ultsonch.2023.106521] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/29/2023] [Accepted: 07/07/2023] [Indexed: 07/22/2023]
Abstract
The sonochemical oxidation activity was investigated for gas saturation and gas sparging under various liquid levels and volumes in 300 kHz sonoreactors. The liquid levels and volumes ranged from 5λ (25 mm, 0.47 L) to 50λ (250 mm, 4.30 L) and two gas mixtures, Ar:O2 (75:25) and N2:O2 (75:25), were used. Two types of reaction kinetics were observed to quantitatively analyze the sonochemical oxidation reactions: zero-order (KI dosimetry: C0 = 60.2 mM) and first-order (Bisphenol A (BPA) degradation: C0 = 0.043 mM). The masses of the sonochemical oxidation reactions were calculated and compared rather than the concentrations to more accurately compare the sonochemical oxidation activity under different liquid volume conditions. First, as the liquid level or volume increased for the zero-order reactions, the concentration of I3- ions representing the volume-averaged activity decreased substantially for gas saturation owing to the increase in liquid volume. However, gas sparging substantially enhanced sonochemical oxidation activity, and the mass of I3- ions representing the total activity remained constant as the liquid level increased from 20λ because of the improved liquid mixing and a shift in the sonochemical active zone. Second, as evidenced by the zero-order reactions, the concentration of BPA decreased considerably as the liquid level or volume increased in the first-order reactions. When gas sparging was used, higher reaction constants were obtained for both gas mixtures, ranging from 40λ to 50λ. However, a comparison of the sonochemical oxidation activity in terms of the degraded mass of BPA was inapplicable as the concentration of BPA decreased substantially and a lack of reactants occurred for the lower liquid level and volume conditions as the irradiation time elapsed. Instead, using the first-order reaction constant, a comparison of the required reaction times for a specific removal efficiency (30%, 60%, and 90%) was proposed. Gas sparging can substantially reduce the reaction time required for a liquid level of 40λ or higher.
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Affiliation(s)
- Seongeun Lee
- Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea; Department of Energy Engineering Convergence, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea
| | - Younggyu Son
- Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea; Department of Energy Engineering Convergence, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea.
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4
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Choi J, Son Y. Effect of dissolved gases on sonochemical oxidation in a 20 kHz probe system: Continuous monitoring of dissolved oxygen concentration and sonochemical oxidation activity. ULTRASONICS SONOCHEMISTRY 2023; 97:106452. [PMID: 37245263 DOI: 10.1016/j.ultsonch.2023.106452] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 05/15/2023] [Accepted: 05/20/2023] [Indexed: 05/30/2023]
Abstract
Dissolved gases have a substantial influence on acoustic cavitation and sonochemical oxidation reactions. Little research on the changes in dissolved gases and the resultant changes in sonochemical oxidation has been reported, and most studies have focused only on the initial dissolved gas conditions. In this study, the dissolved oxygen (DO) concentration was measured continuously during ultrasonic irradiation using an optical sensor in different gas modes (saturation/open, saturation/closed, and sparging/closed modes). Simultaneously, the resulting changes in sonochemical oxidation were quantified using KI dosimetry. In the saturation/open mode using five gas conditions of Ar and O2, the DO concentration decreased rapidly when O2 was present because of active gas exchange with the atmosphere, and the DO concentration increased when 100% Ar was used. As a result, the order of the zero-order reaction constant for the first 10 min (k0-10) decreased in the order Ar:O2 (75:25) > 100% Ar ≈ Ar:O2 (50:50) > Ar:O2 (25:75) > 100% O2, whereas that during the last 10 min (k20-30) when the DO concentration was relatively stable, decreased in the order 100% Ar > Ar:O2 (75:25) > Ar:O2 (50:50) ≈ Ar:O2 (20:75) > 100% O2. In the saturation/closed mode, the DO concentration decreased to approximately 70-80% of the initial level because of ultrasonic degassing, and there was no influence of gases other than Ar and O2. Consequently, k0-10 and k20-30 decreased in the order Ar:O2 (75:25) > Ar:O2 (50:50) > Ar:O2 (25:75) > 100% Ar > 100% O2. In the sparging/closed mode, the DO concentration was maintained at approximately 90% of the initial level because of the more active gas adsorption induced by gas sparging, and the values of k0-10 and k20-30 were almost the same as those in the saturation/closed mode. In the saturation/open and sparging/closed modes, the Ar:O2 (75:25) condition was most favorable for enhancing sonochemical oxidation. However, a comparison of k0-10 and k20-30 indicated that there would be an optimal dissolved gas condition that was different from the initial gas condition. In addition, the mass-transfer and ultrasonic-degassing coefficients were calculated using changes in the DO concentration in the three modes.
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Affiliation(s)
- Jongbok Choi
- Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea
| | - Younggyu Son
- Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea; Department of Energy Engineering Convergence, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea.
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5
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Magnetic Iron Nanoparticles: Synthesis, Surface Enhancements, and Biological Challenges. Processes (Basel) 2022. [DOI: 10.3390/pr10112282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
This review focuses on the role of magnetic nanoparticles (MNPs), their physicochemical properties, their potential applications, and their association with the consequent toxicological effects in complex biologic systems. These MNPs have generated an accelerated development and research movement in the last two decades. They are solving a large portion of problems in several industries, including cosmetics, pharmaceuticals, diagnostics, water remediation, photoelectronics, and information storage, to name a few. As a result, more MNPs are put into contact with biological organisms, including humans, via interacting with their cellular structures. This situation will require a deeper understanding of these particles’ full impact in interacting with complex biological systems, and even though extensive studies have been carried out on different biological systems discussing toxicology aspects of MNP systems used in biomedical applications, they give mixed and inconclusive results. Chemical agencies, such as the Registration, Evaluation, Authorization, and Restriction of Chemical substances (REACH) legislation for registration, evaluation, and authorization of substances and materials from the European Chemical Agency (ECHA), have held meetings to discuss the issue. However, nanomaterials (NMs) are being categorized by composition alone, ignoring the physicochemical properties and possible risks that their size, stability, crystallinity, and morphology could bring to health. Although several initiatives are being discussed around the world for the correct management and disposal of these materials, thanks to the extensive work of researchers everywhere addressing the issue of related biological impacts and concerns, and a new nanoethics and nanosafety branch to help clarify and bring together information about the impact of nanoparticles, more questions than answers have arisen regarding the behavior of MNPs with a wide range of effects in the same tissue. The generation of a consolidative framework of these biological behaviors is necessary to allow future applications to be manageable.
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Son Y, Seo J. Effects of gas saturation and sparging on sonochemical oxidation activity in open and closed systems, Part I: H 2O 2 generation. ULTRASONICS SONOCHEMISTRY 2022; 90:106214. [PMID: 36327919 PMCID: PMC9636189 DOI: 10.1016/j.ultsonch.2022.106214] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/10/2022] [Accepted: 10/27/2022] [Indexed: 06/01/2023]
Abstract
Cavitational/sonochemical activity can be significantly enhanced or reduced depending on the gases dissolved in the liquid. Although many researchers have suggested the order of importance of dissolved gas conditions that affect the degree of sonoluminescence (SL), sonochemiluminescence (SCL), and compound degradation, the most suitable gas condition for sonochemical oxidation reactions is currently unknown. In this study (Part I), the effects of gas saturation and sparging on the generation of H2O2 were investigated in a 28-kHz sonoreactor system. Four gas modes, saturation/closed, saturation/open, sparging/closed, and sparging/open, were applied to Ar, O2, N2, and binary gas mixtures. The change in dissolved oxygen (DO) concentration during ultrasonic irradiation was measured and was used as an indicator of whether the gaseous exchange between liquid and air altered the gas content of the liquid. Considerable difference in the DO concentration was observed for the gas saturation/open mode, ranging from -11.5 mg/L (O2 100 %) to +4.3 mg/L (N2 100 %), while no significant difference was observed in the other gas modes. The change in the gas content significantly reduced the linearity for H2O2 generation, which followed pseudo-zero-order kinetics, and either positively or negatively affected H2O2 generation. Ar:O2 (75:25) and Ar:O2 (50:50) resulted in the highest and second-highest H2O2 generation for both gas saturation and sparging, respectively. In addition, gas sparging resulted in much higher H2O2 generation for all gas conditions compared to gas saturation; this was because of the significant change in the cavitational active zone and concentrated ultrasonic energy, which formed a bulb-shaped active zone, especially for the Ar/O2 mixtures adjacent to the transducer at the bottom. The sparging flow rate and position also significantly affected H2O2 generation; the highest H2O2 generation was obtained when the sparger was placed at the bottom adjacent to the transducer, with a flow rate of 3 L/min. In Part II, the generation of nitrogen oxides, including nitrite (NO2-) and nitrate (NO3-), was investigated using the same ultrasonic system with three gas modes: saturation/open, saturation/closed, and sparging/closed.
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Affiliation(s)
- Younggyu Son
- Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea; Department of Energy Engineering Convergence, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea.
| | - Jieun Seo
- Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea; Environment Research Division, Gyeongsangbuk-do Government Public Institute of Health & Environment, Yeongcheon 38874, Republic of Korea
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7
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Wang X, Mori Y, Tsuchiya K. Periodicity in ultrasonic atomization involving beads-fountain oscillations and mist generation: Effects of driving frequency. ULTRASONICS SONOCHEMISTRY 2022; 86:105997. [PMID: 35417794 PMCID: PMC9018148 DOI: 10.1016/j.ultsonch.2022.105997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 03/14/2022] [Accepted: 03/30/2022] [Indexed: 06/14/2023]
Abstract
Ultrasonic atomization induced by high driving frequency, generally on the order of 1 MHz or higher, could involve a liquid fountain in the form of a corrugated jet, or a chain of "beads" of submillimeter diameter in contact. This study concerns dynamics/instability of such beads fountain, observed under lower input power density (≤ 6 W/cm2) of the "flat" ultrasound transducer with a "regulating" nozzle equipped, exhibiting time-varying characteristics with certain periodicity. High-speed, high-resolution images are processed for quantitative elucidation: frequency analysis (fast Fourier transform) and time-frequency analysis (discrete wavelet transform) are employed, respectively, to evaluate dominant frequencies of beads-surface oscillations and to reveal factor(s) triggering mist emergence. The resulting time variation in the measured (or apparent) fountain structure, associated with the recurring-beads size scalable to the ultrasound wavelength, subsumes periodic nature predictable from simple physical modeling as well as principle. It is further found that such dynamics in (time-series data for) the fountain structure at given height(s) along a series of beads would signal "bursting" of liquid droplets emanating out of a highly deformed bead often followed by a cloud of tiny droplets, or mist. In particular, the bursting appears to be not a completely random phenomenon but should concur with the fountain periodicity with a limited extent of probability.
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Affiliation(s)
- Xiaolu Wang
- Dept. of Chemical Engineering and Materials Science, Doshisha Univ., Kyotanabe, Kyoto 610-0321, Japan
| | - Yasushige Mori
- Dept. of Chemical Engineering and Materials Science, Doshisha Univ., Kyotanabe, Kyoto 610-0321, Japan
| | - Katsumi Tsuchiya
- Dept. of Chemical Engineering and Materials Science, Doshisha Univ., Kyotanabe, Kyoto 610-0321, Japan.
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Lee D, Na I, Son Y. Effect of liquid recirculation flow on sonochemical oxidation activity in a 28 kHz sonoreactor. CHEMOSPHERE 2022; 286:131780. [PMID: 34358887 DOI: 10.1016/j.chemosphere.2021.131780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 07/20/2021] [Accepted: 08/01/2021] [Indexed: 05/14/2023]
Abstract
Sonochemical oxidation activity may be significantly enhanced by optimizing the geometric factors of a sonoreactor and implementing additional physical actions, such as mechanical mixing and gas sparging. This study investigates the effects of liquid recirculation flow on sonochemical oxidation reactions. This was carried out through experimental testing with a 28 kHz bath-type sonoreactor under various liquid heights and flow rates, ranging from 1λ to 4.0λ and 1.5-6.0 L/min, respectively. The potassium iodide (KI) dosimetry and sonochemiluminescence methods were used in the experiment. With an increase in the liquid height/volume, the pseudo zero-order kinetic constant and the mass of triiodide (I3-) ions fluctuated. The optimal liquid height was 2.0λ, 2.5λ, and 3.0λ, based on the appropriate formation of a cavitation active zone in the reactor. The introduction of a liquid recirculation flow led to a large reduction in sonochemical activity due to the shrinkage of the cavitation active zone. However, the sonochemical activity increased at higher flow rates through the capture of ultrasonic energy at the bottom zone. This increase was attributed to the formation of a strong and expanded active zone limited to the reactor bottom to the height of the recirculation flow. The results demonstrate that applying a high rate liquid flow adjacent to the transducer module may be beneficial for enhanced sonochemical activity.
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Affiliation(s)
- Dukyoung Lee
- Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi, 39177, Republic of Korea; Department of Energy Engineering Convergence, Kumoh National Institute of Technology, Gumi, 39177, Republic of Korea
| | - Iseul Na
- Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi, 39177, Republic of Korea; Department of Energy Engineering Convergence, Kumoh National Institute of Technology, Gumi, 39177, Republic of Korea
| | - Younggyu Son
- Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi, 39177, Republic of Korea; Department of Energy Engineering Convergence, Kumoh National Institute of Technology, Gumi, 39177, Republic of Korea.
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9
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Technoeconomic analysis of oxygen-nitrogen separation for oxygen enrichment using membranes. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.118703] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Choi J, Lee H, Son Y. Effects of gas sparging and mechanical mixing on sonochemical oxidation activity. ULTRASONICS SONOCHEMISTRY 2021; 70:105334. [PMID: 32932226 PMCID: PMC7786622 DOI: 10.1016/j.ultsonch.2020.105334] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/28/2020] [Accepted: 08/28/2020] [Indexed: 05/20/2023]
Abstract
The effects of air sparging (0-16 L min-1) and mechanical mixing (0-400 rpm) on enhancing the sonochemical degradation of rhodamine B (RhB) was investigated using a 28 kHz sonoreactor. The degradation of RhB followed pseudo first-order kinetics, where sparging or mixing induced a large sonochemical enhancement. The kinetic constant varied in three stages (gradually increased → increased exponentially → decreased slightly) as the rate of sparging or mixing increased, where the stages were similar for both processes. The highest sonochemical activity was obtained with sparging at 8 L min-1 or mixing at 200 rpm, where the standing wave field was significantly deformed by sparging and mixing, respectively. The cavitational oxidation activity was concentrated at the bottom of the sonicator when higher sparging or mixing rates were employed. Therefore, the large enhancement in the sonochemical oxidation was attributed mainly to the direct disturbance of the ultrasound transmission and the resulting change in the cavitation-active zone in this study. The effect of the position of air sparging and mixing was investigated. The indirect inhibition of the ultrasound transmission resulted in less enhancement of the sonochemical activity. Moreover, the effect of various sparging gases including air, N2, O2, Ar, CO2, and an Ar/O2 (8:2) mixture was compared, where all gases except CO2 induced an enhancement in the sonochemical activity, irrespective of the concentration of dissolved oxygen. The highest activity was obtained with the Ar/O2 (8:2) mixture. Therefore, it was revealed that the sonochemical oxidation activity could be further enhanced by applying gas sparging using the optimal gas.
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Affiliation(s)
- Jongbok Choi
- Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea; School of Civil, Environmental, and Architectural Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Hyeonjae Lee
- Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea; R&D Center, Changmyoung Industry Co., Yangju 11426, Republic of Korea
| | - Younggyu Son
- Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea; Department of Energy Engineering Convergence, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea.
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11
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Yang Y, Zheng Z, Zhang D, Zhou C, Zhang X. Ultrasonic degradation of nitrosodipropylamine (NDPA) and nitrosodibutylamine (NDBA) in water. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:29143-29155. [PMID: 32424764 DOI: 10.1007/s11356-020-09040-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 04/22/2020] [Indexed: 06/11/2023]
Abstract
Nitrosodipropylamine (NDPA) and nitrosodibutylamine (NDBA), two highly toxics and carcinogenic disinfection by-products, cannot be efficiently removed by conventional water treatment processes, while the ultrasound treatment was developed as a promising alternative. In this work, nitrosodipropylamine (NDPA) and nitrosodibutylamine (NDBA) are degraded by ultrasound treatment. Greater than 99% of NDPA and NDBA mixing solution could be decomposed within 60 min at neutral pH under optimal ultrasound power and frequency settings of 100 W and 600 kHz, respectively. Free radical reactions (OH•) played a significant role and the reaction sites were predominately at the bubble interface. The degradation of both NDPA and NDBA exhibited pseudo-first-order degradation kinetics, and the rate constant kapp was influenced by a number of factors including ultrasonic frequency, power, initial concentration, initial pH, various anions and cations frequently present in drinking water, hydroxyl radical scavengers, and water matrices, especially the promoting effect of various anions and cations and water matrices. The results of this study suggest the potential for ultrasound treatment as a method for removing NAms from water.
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Affiliation(s)
- Yiqiong Yang
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, China
| | - Zenghui Zheng
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, China
| | - Dongfeng Zhang
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, China
| | - Chao Zhou
- Shanghai Municipal Planning & Design Institute Co., Ltd., Shanghai, 200031, China
| | - Xiaodong Zhang
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, China.
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12
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Son Y, No Y, Kim J. Geometric and operational optimization of 20-kHz probe-type sonoreactor for enhancing sonochemical activity. ULTRASONICS SONOCHEMISTRY 2020; 65:105065. [PMID: 32199254 DOI: 10.1016/j.ultsonch.2020.105065] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/03/2020] [Accepted: 03/10/2020] [Indexed: 05/14/2023]
Abstract
The use of a 20-kHz probe-type sonicator irradiating downward in a 500 mL vessel was optimized for the enhancement of the sonochemical activity in terms of the geometric and operational factors. These factors included the probe immersion depth (the vertical position of the probe), input power, height of the liquid from the bottom, horizontal position of the probe, and thickness of bottom plate The sonochemical oxidation reactions were investigated both quantitatively and qualitatively using calorimetry, KI dosimetry, and luminol (Sonochemiluminescence, SCL) techniques. The sonochemical activity was very positively affected by the vertical boundaries. The highest sonochemical activity was obtained when the probe was placed close to the bottom of the vessel (immersion depth of 60 mm), with a high input power (input power of 75%), and optimal liquid height condition (liquid height of 70 mm). The SCL image analysis showed that the cavitational activity zone gradually expanded around the probe body and changed into a circular shape as the experimental conditions were optimized, and consequently the sonochemical activity increased. The formation of a large bright circular-shaped activity zone could be attributed to the strong reflections of the ultrasound firstly, at the vessel bottom and secondly, at the liquid surface. On the other hand, the cavitational activity zone and the sonochemical activity were negatively affected by the horizontal boundaries when the probe was placed close to the side wall of the vessel. In addition, it was found that the sonochemical activity was also significantly affected by the thickness of the support plate owing to the reflection and transmission of the ultrasound at the boundary between the liquid and the solid media.
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Affiliation(s)
- Younggyu Son
- Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea.
| | - Yunsung No
- Department of Environmental Engineering, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea
| | - Jeonggwan Kim
- Soil Environment Center, Korea Environmental Industry & Technology Institute, Seoul 03367, Republic of Korea.
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13
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Zhang BC, Jia XJ, Li FY, Sun YH. Research on the Effect of Molten Salt Ultrasonic Composite Cleaning for Paint Removal. ACS OMEGA 2019; 4:17072-17082. [PMID: 31646254 PMCID: PMC6796236 DOI: 10.1021/acsomega.9b02880] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 09/20/2019] [Indexed: 06/10/2023]
Abstract
Aiming at paint removal on hydraulic cylinder, the effect of molten salt ultrasonic composite cleaning was studied. First, the mechanism of molten salt cleaning and ultrasonic cleaning was reviewed. To further describe the composite cleaning mechanism, the components and internal structure of paint were analyzed by scanning electron microscopy and Fourier transform infrared. Results showed that the paint had a significant layered structure. The total thickness was about 100 μm, and the main components were organic matters, including ester groups, epoxy groups, and aromatic compounds. Then, combining with thermal environment, cleaning medium's property, and ultrasound, the composite cleaning mechanism was described in terms of three aspects: thermal effect, chemical reaction, and ultrasonic effect. Besides, the reason why this composite cleaning had good effect on paint removal, compared to paint heated in air, was explained through dynamic analysis, which was the reduction of reaction activation energy from 114.4 kJ/mol of paint alone to 74.1 kJ/mol.
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Affiliation(s)
- Bao-cai Zhang
- Key Laboratory of
High Efficiency and Clean Mechanical Manufacture (Ministry of Education),
School of Mechanical Engineering, Shandong
University, Jinan 250061, China
- National
Demonstration Center for Experimental Mechanical Engineering Education
(Shandong University), Jinan 250061, China
| | - Xiu-jie Jia
- Key Laboratory of
High Efficiency and Clean Mechanical Manufacture (Ministry of Education),
School of Mechanical Engineering, Shandong
University, Jinan 250061, China
- National
Demonstration Center for Experimental Mechanical Engineering Education
(Shandong University), Jinan 250061, China
| | - Fang-yi Li
- Key Laboratory of
High Efficiency and Clean Mechanical Manufacture (Ministry of Education),
School of Mechanical Engineering, Shandong
University, Jinan 250061, China
- National
Demonstration Center for Experimental Mechanical Engineering Education
(Shandong University), Jinan 250061, China
| | - Yi-hang Sun
- Key Laboratory of
High Efficiency and Clean Mechanical Manufacture (Ministry of Education),
School of Mechanical Engineering, Shandong
University, Jinan 250061, China
- National
Demonstration Center for Experimental Mechanical Engineering Education
(Shandong University), Jinan 250061, China
| |
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