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Ultrasonics Sonochemistry

H Ohrdes, I Ille, J Twiefel, J Wallaschek, R Nogueira, K-H Rosenwinkel
Sonochemical processes applied to wastewater treatment have an influence on the behavior of ultrasonic systems. This is especially due to the load characteristic of the sonochemical process itself and the temperature increase caused by internal damping within the converter. Hence, a controlling device is needed to guarantee the operation in resonance and to keep the vibration amplitude constant. This paper presents a digital control system for the operation of weak to strong damped ultrasonic devices and its application for inactivating Escherichia coli in wastewater...
April 16, 2017: Ultrasonics Sonochemistry
Zhilin Wu, Francisco J Yuste-Córdoba, Pedro Cintas, Zhansheng Wu, Luisa Boffa, Stefano Mantegna, Giancarlo Cravotto
This paper reports that ultrasonic (US) and hydrodynamic cavitation (HC) are efficient strategies for the environmental remediation of cork wastewater (CW). It is necessary to remove toxic, inhibitory or refractory organic matter from CW using physical and chemical techniques (pre-treatment) prior to performing conventional biological treatment. After this biological treatment, it is also critical to further decontaminate (post-treatment) in order to meet the discharge limitation. The pre-treatment of diluted CW using Fenton oxidation (FE) alone led to COD and polyphenol (PP) removal values of 30% and 61%, respectively, while HC and US resulted in 83-90% increases in COD reduction and 26-33% increases in PP reduction...
April 13, 2017: Ultrasonics Sonochemistry
Lisarb O Diehl, Thais L Gatiboni, Paola A Mello, Edson I Muller, Fabio A Duarte, Erico M M Flores
In view of the increasing demand for rare-earth elements (REE) in many areas of high technology, alternative methods for the extraction of these elements have been developed. In this work, a process based on the use of ultrasound for the extraction of REE from carbonatite (an igneous rock) is proposed to avoid the use of concentrated reagents, high temperature and excessive extraction time. In this pioneer work for REE extraction from carbonatite rocks in a preliminary investigation, ultrasonic baths, cup horn systems or ultrasound probes operating at different frequencies and power were evaluated...
April 12, 2017: Ultrasonics Sonochemistry
Yuning Zhang, Yuning Zhang
Chaotic oscillation of bubbles in liquids reduces the efficiency of the sonochemical system and should be suppressed in the practical applications. In the present paper, a chaos control method based on the dual-frequency approach is numerically investigated and is proved to be an effective method even for cases with intensive energy input. It was found that the chaos could be successfully suppressed by the application of dual-frequency approach in a wide range of parameter zone (even with high acoustic pressure amplitude)...
April 9, 2017: Ultrasonics Sonochemistry
N V Dezhkunov, A Francescutto, L Serpe, R Canaparo, G Cravotto
The way in which a cavitation zone develops in a focused pulsed ultrasound field is studied in this work. Sonoluminescence (SL), total hydrophone output and cavitation noise spectra have been recorded across a gradual, smooth increase in applied voltage. It is shown that the cavitation zone passes through a number of stages of evolution, according to increasing ultrasound intensity, decreasing pulse period and increasing ultrasound pulse duration. Sonoluminescence is absent in the first phase and the hydrophone output spectra consists of a main line with two or three harmonics whose intensity is much lower than that of the main (fundamental) line...
April 6, 2017: Ultrasonics Sonochemistry
Matheus F Pedrotti, Michele S P Enders, Leticia S F Pereira, Marcia F Mesko, Erico M M Flores, Cezar A Bizzi
Water removal is an essential step during crude oil production due to several problems such as increased transportation costs and high corrosion rate due to dissolved salts. Indirect low frequency ultrasonic energy (US), using baths, has been recently proposed as an effective alternative for crude oil demulsification. However, the reactor position during sonication and its influence on the demulsification efficiency for crude oil has not been evaluated. In this sense, the aim of this study was to develop an automated system based on an open source hardware for mapping the acoustic field distribution in an US bath operating at 35kHz using a hydrophone...
April 2, 2017: Ultrasonics Sonochemistry
Yuning Zhang, Zhongyu Guo, Yuhang Gao, Xiaoze Du
Presence of bubbles in liquids could significantly alter the acoustic waves in terms of wave speed and attenuation. In the present paper, acoustic wave propagation in bubbly flows with gas, vapor and gas/vapor mixtures is theoretically investigated in a wide range of parameters (including frequency, bubble radius, void fraction, and vapor mass fraction). Our finding reveals two types of wave propagation behavior depending on the vapor mass fraction. Furthermore, the minimum wave speed (required for the closure of cavitation modelling in the sonochemical reactor design) is analyzed and the influences of paramount parameters on it are quantitatively discussed...
March 29, 2017: Ultrasonics Sonochemistry
Shanshan Jiang, Junzhou Ding, Juan Andrade, Taha M Rababah, Ali Almajwal, Mahmoud M Abulmeaty, Hao Feng
The effect of a pH-shifting and ultrasound combined process on the functional properties and structure of pea protein isolate (PPI) was investigated. PPI dispersions were adjusted to pH 2, 4, 10, or 12, treated by power ultrasound for 5min, and incubated for 1h before the sample pH was brought back to neutral. After treatment, water solubility, protein aggregate size, solution turbidity, surface hydrophobicity (Ho), free sulfhydryl content (SH), and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of the soluble PPI were determined...
March 28, 2017: Ultrasonics Sonochemistry
Filipe Gomes, Harsh Thakkar, Anna Lähde, Bram Verhaagen, Aniruddha B Pandit, David Fernández Rivas
In this paper we report our most recent attempts to tackle a notorious problem across several scientific activities from the ultrasonics sonochemical perspective: reproducibility of results. We provide experimental results carried out in three different laboratories, using the same ingredients: ultrasound and a novel cavitation reactor bag. The main difference between the experiments is that they are aimed at different applications, KI liberation and MB degradation; and exfoliation of two nanomaterials: graphene and molybdenum disulfide...
March 24, 2017: Ultrasonics Sonochemistry
Gregory Chatel
Based on the analyses of papers from the literature, and especially those published in Ultrasonics Sonochemistry journal, the contribution of sonochemistry to green chemistry area has been discussed here. Important reminders and insights on the good practices and considerations have been made to understand and demonstrate how sonochemistry can continue to efficiently contribute to green chemistry area in the further studies.
March 15, 2017: Ultrasonics Sonochemistry
L Baissac, C C Buron, L Hallez, P Berçot, J-Y Hihn, L Chantegrel, G Gosse
PMMA particle synthesis was performed from MMA (methyl methacrylate) and water mixtures, exposed to different ultrasonic systems and frequencies. The sonication sequence was 20kHz→580kHz→858kHz→1138kHz, and the solution was sampled after each irradiation step for polymerization. Effects of sonication parameters (time, power), polymerization method (thermo-initiated or photo-initiated), use of small amounts of surfactant (Triton X-100™ or Tween® 20) and initial MMA quantity were investigated on particle size and synthesis yields...
March 14, 2017: Ultrasonics Sonochemistry
Aymeric Nevers, Loïc Hallez, Francis Touyeras, Jean-Yves Hihn
An attractive possibility for influencing microstructures of electrodeposited coatings, and therefore their properties such as hardness, brightness etc. resides in the use of ultrasound. This method is particularly competitive as it may result in a reduction of chemical use, or even in the complete suppression of chemicals. This paper deals with silver coatings depending strongly on current density, with two main categories identified by X-ray diffraction: one poorly structured and the other following the [110] orientation...
February 27, 2017: Ultrasonics Sonochemistry
Gareth J Price, Mohsan Nawaz, Tariq Yasin, Saira Bibi
Multi-walled carbon nanotubes (CNTs) have been treated using 20kHz ultrasound in combination with dilute nitric and sulfuric acids at much lower concentrations than previously reported. The measurements revealed an optimum set of sonication conditions (in this case 30min at 12Wcm(-2)) exists to overcome aggregation of the nanotubes and to allow efficient dispersion in ethanol or in chitosan. Transmission electron microscopy and Raman spectroscopy suggested the removal of amorphous material and reduction of the CNT diameter as well as modifications to their defect structures...
February 21, 2017: Ultrasonics Sonochemistry
Asu Ziylan-Yavaş, Nilsun H Ince
The study is the assessment of commercial γ-Al2O3 and its sonolytically modified nanocomposite in catalytic ozonation of paracetamol (PCT), which is an emerging water contaminant and a highly reactive compound with ozone. The results showed that commercial alumina was ineffective regardless of the solution pH, due to the low affinity of the catalyst surface for PCT and the high reactivity of the solute with molecular ozone. The modified catalyst, which was synthesized by decoration of the original surface with nanoparticles of platinum provided considerable improvement in the performance of the catalyst, particularly in mineralization of the target compound...
February 16, 2017: Ultrasonics Sonochemistry
Rajashree H Jawale, Parag R Gogate
Pesticides have been the major contributors to the growth of agricultural productivity, but the wide spread use in the fields and discharge from the manufacturing industries have also contributed to environmental concerns. In the present work, degradation of triazophos (O,O-diethyl-O-(1-phenyl-1H-1,2,4-triazol-3-yl) phosphorothioate) as a model pollutant has been investigated using high volume continuous ultrasonic flow cell for the first time. Effect of power dissipation and initial pH on the extent of triazophos degradation using acoustic cavitation has been investigated initially...
February 15, 2017: Ultrasonics Sonochemistry
Florian Roy, Abdeslam Et Taouil, Fabrice Lallemand, Olivier Heintz, Virginie Moutarlier, Jean-Yves Hihn
Self-assembling of undecanthiol (C11SH) on polycrystalline gold was investigated under two different conditions. The kinetics of C11SH grafting was studied without and under high frequency ultrasound irradiation. Two electrochemical experiments were extensively carried out in order to determine electrochemical surface blocking of adsorbed layers as a function of grafting time: chronoamperometry in-situ monitoring and cyclic voltammetry. Interestingly, the grafting process is highly accelerated under sonication, and C11SH modified substrates of good quality are obtained after 3h' immersion under ultrasound irradiation...
February 11, 2017: Ultrasonics Sonochemistry
(no author information available yet)
No abstract text is available yet for this article.
February 1, 2017: Ultrasonics Sonochemistry
Farid Chemat, Muthupandian Ashokkumar
No abstract text is available yet for this article.
January 30, 2017: Ultrasonics Sonochemistry
Mehdi Dastkhoon, Mehrorang Ghaedi, Arash Asfaram, Alireza Goudarzi, Seyyedeh Maryam Mohammadi, Shaobin Wang
In this work, ultrasound-assisted adsorption of an anionic dye, sunset yellow (SY) and cationic dyes, malachite green (MG), methylene blue (MB) and their ternary dye solutions onto Cu@ Mn-ZnS-NPs-AC from water aqueous was optimized by response surface methodology (RSM) using the central composite design (CCD). The adsorbent was characterized using Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX) and EDX mapping images. The effects of various parameters such as pH, sonication time, adsorbent mass and initial concentrations of SY, MG and MB were examined...
July 2017: Ultrasonics Sonochemistry
Chinmay N Gajendragadkar, Parag R Gogate
The current work deals with the value addition of lactose by transforming into hydrolyzed lactose syrup containing glucose and galactose in major proportion using the novel approach of ultrasound assisted acid catalyzed lactose hydrolysis. The hydrolysis of lactose was performed in ultrasonic bath (33kHz) at 50% duty cycle at different temperatures as 65°C and 70°C and two different hydrochloric acid (HCl) concentrations as 2.5N and 3N. It was observed that acid concentration, temperature and ultrasonic treatment were the major factors in deciding the time required to achieve ∼90% hydrolysis...
July 2017: Ultrasonics Sonochemistry
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