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The search for renewable energy sources to replace fossil fuel has made lignin a promising carbon-containing resource. In this paper, LaNiO 3 perovskite catalyst supported by mesoporous carrier with specific pore structure was prepared by the pore filling of MCM-41 with citrate complex precursors of nickel and lanthanum. Then the catalysts applied to maize straw lignin depolymerization. The results of low-angle XRD, N 2 adsorption-desorption, IR spectroscopy and SEM confirmed that the catalyst has been successfully manufactured. Based on the yield of phenolic monomer, low molecular weight lignin derived bio-oil and high molecular weight lignin derived bio-oil as standard, the catalyst showed best catalytic effect when the reaction temperature was 250 °C, the reaction time was 6 h, the ratio of lignin to catalyst mass was 5: 1 and with ultrasonic assist. The yield of phenolic monomer was 11.46 wt% and that of bio-oil was 68.0 wt%. In general, this method is an excellent embodiment of the principle of Lignin-first as well as an excellent strategy for the production of value-added phenolics and high-quality bio-oils from lignin. It plays an important role in promoting the high value utilization of lignin in the future., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

An efficient method based on ultrasound-assisted emulsification microextraction followed by injection-port derivatization GC analysis was developed to determine 2,4-dichlorophenoxyacetic acid (2,4-D) and 4-chloro-2-methylphenoxyacetic acid (MCPA) in natural water samples. In this procedure, 12.5 μL of 1-undecanol was injected slowly into a 12 mL home-designed centrifuge glass vial containing an aqueous sample of the analytes located inside an ultrasonic water bath. The resulting emulsion was centrifuged, and 1 μL of the separated organic solvent together with 1 μL of the derivatization reagent were injected into a GC equipped with a flame ionization detector. Several factors that influence the derivatization and extraction were optimized. Under the optimal conditions, the LODs were 0.33 and 1.7 μg/L for MCPA and 2,4-D, respectively. Preconcentration factors of 670 and 836 were obtained for MCPA and 2,4-D, respectively. The precision of the proposed method was evaluated in terms of repeatability, which was <5.7% (n = 5). The applicability of the proposed method was evaluated by extraction and determination of chlorophenoxyacetic acids from some natural waters, which indicated that the matrices of natural waters have no significant effect on the extraction and derivatization efficiency of this method., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

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Herein, we developed a novel integrated device to perform phase separation based on ultrasound-assisted, salt-induced, liquid-liquid microextraction for determination of five fluoroquinones in meats by HPLC analysis. The novel integrated device consisted of three simple HDPE (high density polyethylene) parts that were used to separate the solvent from the aqueous solution prior to retrieving the extractant. The extraction parameters were optimized using the response surface method based on central composite design: 589μL of acetone solvent, pH2.1, 4.1min extraction time and 3.5g of Na2SO4. The limits of detection were 0.056-0.64 μgkg(-1) and recoveries were 87.2-110.6% for the five fluoroquinones in muscle tissue from fish, chicken, pork and beef. This method is easily constructed from inexpensive materials, extraction efficiency is high, and the approach is compatible with HPLC analysis. Thus, it has excellent prospects for sample pre-treatment and analysis of fluoroquinones in meat samples.

Unburnt coal in a boiler gets converted to fly ash and bottom ash. Fly ash particles travel along with flue gas and get deposited on heat transfer surfaces along the way. Fouling and slagging are phenomena associated with fly ash deposits which could potentially damage the heat transfer surface, if left unattended. Sodium and potassium are directly linked to the deposition of fly ash, as they form a molten salt film which aids in sticking of fly ash particles. Ultrasound is one of the mitigation techniques used to prevent ash deposition. This study aims at reducing the concentrations of alkali metals in coal as a pretreatment method, using ultrasound. Two modes of operation are chosen: continuous and pulsed. A solvent has been used to enhance the leaching process. In the pulsed mode, the sample is alternated between periods of exposure and nonexposure. A maximum leaching rate of 62% for potassium and 24.5% for sodium was observed in the continuous mode at 360 kHz of operation while pulsed mode of operation showed a maximum leaching rate of 91.3% and 54.4% for potassium and sodium operated at 360 kHz, respectively. The experimental data have been fit to the shrinking core model, and the rate-controlling step has been found to be surface diffusion of reactants into the core. The effect of various parameters is analyzed and compared for pulsed and continuous modes of operation. Order of the reaction, activation energy, and leaching kinetics are obtained by fitting the data into the shrinking core model. [ABSTRACT FROM AUTHOR]

Highlights • Leaching silver without oxygen and ammonia to be achieved by ultrasonic field. • Ultrasonic enhanced leaching mechanism has a detailed analysis. • The dynamic models were analyzed in detail separately. Abstract The process to fast recovery of silver from the spent symbiosis lead-zinc mine enhanced by ultrasound has been developed. A system composed of thiosulfate and the spent symbiosis lead-zinc mine under ultrasound radiation is researched and compared with regular methods to prove the superiority of ultrasound enhanced leaching. Oxygen is not provided by the usual way but by the cavitation of ultrasound, and the effect of ultrasonic enhanced leaching is more obvious than oxygen enhanced leaching effect. We are more authoritative by combining some valuable literature after conducting systematic experiments. The process mechanism was analyzed by fire assaying, XRD, XRF, SEM and EDS. The optimal conditions were found out through single factor experiments: stirring rate of 300 rpm, thiosulfate concentration of 75 g/L, leaching temperature of 303 K, PH of 5, leaching time of 2 h and the ultrasound power of 100 W. And the leaching rate is 77.34% under the best conditions. When the ultrasonic experiment has the same parameters as the normal, the leaching rate at five minutes under ultrasonic conditions was 73.88%, while the leaching rate was only 72.51% at two hours under normal conditions. The apparent activation energy under conventional and ultrasonic conditions is 12.47 kJ/mol and 12.35 kJ/mol, respectively, and it is proved that both are controlled by diffusion. [ABSTRACT FROM AUTHOR]

• Increasing the value of agricultural residue through ultrasonics. • Ultrasonic technology for pretreatment and valorization of biomass. • Unique characteristics of bioproducts obtained from agricultural residue. • Ultrasonics vs Conventional methods: Advantages and Disadvantages. • Potential to exploit ultrasonic technology for large-scale application. The utilization of agricultural residues to obtain biocompounds of high-added value has significantly increased in the past decades. The conversion of agro-based residues into valuable products appears to be an economically efficient, environment-friendly, and protracted waste management practice. The implementation of ultrasonic technologies in the conversion of value-added goods from agricultural waste materials through pre-treatment and valorization processes has imparted many advantageous effects including rapid processing, effective process performance, minimization of processing steps, minimal dependency on harmful chemicals, and an increased yield and properties of bio-products. To further enliven the literature and inspire new research investigations, this review covers the comprehensive work including theoretical principles, processes, and potential benefits of ultrasonic treatment technologies to assist the production of bio-products which emphasize the extraction yield and the characteristic of the end-product extracted from agriculture residues. A detailed evaluation of these methods and key aspects impacting their performance as well as the features and shortcomings of each ultrasound-assisted approach is also discussed. This review also addressed some of the challenges associated with using ultrasonic irradiation and proposed several potential techniques to maximize productivity. Understanding the concept of ultrasonication technique allow the academician and industrial practitioners to explore the possibility of applying a greener and sustainable approach of biomass extraction to be translated into higher scale production of commercial products. [ABSTRACT FROM AUTHOR]

Waterborne nanoemulsion of diglycidyl ether of bisphenol A type epoxy resin (DGEBA) with droplet size of around 124 nm was prepared by using an ultrasonic-assisted supercritical carbon dioxide (scCO 2 ) technique in an autoclave reactor at a low temperature (32 °C). A view cell positioned in-line with the ultrasonic probe allowed observation of the emulsification process. From the image analysis and droplet size measurement, the influence mechanisms of the ultrasonic power, the degree of mixing of scCO 2 with DGEBA, the adding amount of emulsifier, and the system pressure on emulsification process and emulsion droplet size were investigated. In the emulsification process, scCO 2 penetrated into the mixture and absorbed on the DGEBA molecular. The interactions between CO 2 and the functional groups of DGEBA reduced the chain-chain interactions of polymer segments and therefore efficiently reduced the viscosity of DGEBA at a low temperature. Meantime, the cavitation and acoustic streaming of ultrasound provided a shear force for the nanoemulsification and a disturbance force for the homogeneity of the emulsion. Therefore, the combination of scCO 2 and ultrasonication made it possible to prepare a long-term stable nanoemulsion under a low temperature. This ultrasonic-assisted scCO 2 emulsification method provides an efficient and solvent-free process for the preparation of waterborne nanoemulsions of, for example, some heat-sensitive and water-insoluble active substances at low temperature. [ABSTRACT FROM AUTHOR]

[Display omitted] • The highly selective separation of palladium from spent catalyst by ozone/ultrasonic is proposed. • The leaching percentage of palladium is 93.7% at low-acid medium of 0.4 M. • The leaching process is driven by ultrasonic disaggregating of the cladding layer and active free radicals. It is of great significance to consider the recovery of palladium from spent catalyst in terms of resource reserve and environmental protection. However, the leaching percentage of palladium is limited by high oxidation potential and cladding layer. In order to solve this process problem, external field enhancement method with ultrasonic-assisted ozone is proposed for the recycling of palladium in this study. Mechanical and cavitation effects of ultrasonic can destroy cladding layer and promote solid–liquid interface reaction. The highly oxidizing free radicals generated by ultrasonic excitation of ozone can improve the oxidation of the reaction system and accelerate the oxidation rate of palladium. The leaching percentage of palladium is 93.7% under ultrasonic/ozone condition, which is 23.7% higher than that under conventional conditions. The leaching reaction kinetics shows that the reaction barrier is reduced and the apparent activation energy is reduced by 35.25 kJ/mol after introducing ultrasound and ozone. Additionally, mineralogical analysis is carried out to analyze the enhanced leaching mechanism of palladium. This work demonstrates the value of advanced oxidation process with ultrasonic-assisted ozone in efficient and green recovery of precious metals from secondary resources. [ABSTRACT FROM AUTHOR]

An ultra fast decopperization method from the anode slime has been developed based on the ultrasound-assisted leaching. The effects of parameters such as ultrasound power, leaching time, sulfuric acid concentration and liquid/solid ratio were investigated. Under optimum conditions, the concentration of Cu in residue was only 2.64%. The removal efficiency increases considerably and the decopperization time was significantly shortened comparing with conventional method (>10%, 24 h). Se and Te have not been detected in lixivium, indicating the selective leaching of Cu. In addition, the mineralogical characteristics of the untreated anode slime and the residues after ultrasound-assisted decopperization are investigated. The results revealed that the increasing of decopperization efficiency was attributed to the change of the phase composition and the morphology and size of samples during ultrasound-assisted decopperization. [ABSTRACT FROM AUTHOR]

Ultrasound-assisted (UA) and supercritical CO 2 technologies (SCO 2 ) were used to modify the chitin surface and, improve its adsorption characteristics regarding to cobalt. Chitin, before and after the treatments, was characterized by N 2 adsorption isotherms (BET), infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Unmodified and surface modified chitins were used as adsorbents to remove cobalt from aqueous solutions. The adsorption study was performed by equilibrium isotherms and kinetic curves. The chitin particle characteristics, such as, surface area, pore volume and porosity were improved by the UA and SCO 2 treatments. The crystallinity index decreased after the UA and SCO 2 treatments, and also, intense surface modifications were observed. Langmuir and Freundlich models were adequate to represent the adsorption equilibrium. The maximum adsorption capacities were 50.03, 83.94 and 63.08 mg g −1 for unmodified chitin, UA surface modified chitin and SCO 2 surface modified chitin. The adsorption kinetic curves were well represented by the pseudo-second order model. UA and SCO 2 technologies are alternatives to modify the chitin surface and improve its adsorption characteristics. [ABSTRACT FROM AUTHOR]

This work focuses on the ultrasound-assisted hydrolysis of yam to obtain fermentable sugars using phosphoric acid or enzymes as catalysts. In the chemical and enzymatic hydrolyses the effects of temperature and catalyst concentration on the amount of fermentable sugar released were evaluated. The same experiment was carried out with and without ultrasound. For chemical hydrolyses, the maximum amounts of fermentable sugars obtained were 0.155 g sugar g −1 dry material and 0.205 g sugar g −1 dry material, whereas for enzymatic hydrolysis the maximum fermentable sugars obtained were 0.32 g sugar g −1 dry material and 0.42 g sugar g −1 dry material, without and with ultrasound, respectively. These experiments demonstrated that the amount of fermentable sugars differs according to the type of hydrolysis applied. In this work, ultrasound increased the yield for chemical and enzymatic hydrolysis, showing a promising technology to be used for hydrolysis. [ABSTRACT FROM AUTHOR]

Background: Extraction prior to component analysis is the primary step in the recovery and isolation of bioactive phytochemicals from plant materials. Methods: Response surface methodology was applied to optimize ultrasound-assisted extraction conditions followed by ultra high performance liquid chromatography (UHPLC) to achieve high catechin, myricetin, and quercetin contents, and high antioxidant and anticancer activities in the curry leaf extracts. The antioxidant and anticancer activities of the leaf extracts were determined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assays, respectively. The central composite experimental design (3-level, 3-factorial) was employed to consider the effects of ultrasonic power (80-150 W), temperature (40-80°C), and methanol dilution (40-80%) on the properties of the curry leaf extracts. Results: It was found that ultrasonic power of 145.49 W at 55.9°C with 80% methanol was the most appropriate set of conditions for the extraction of catechin, myricetin, and quercetin from curry leaves with the consequent high antioxidant activity. Using the optimum extraction conditions, the extraction yields of catechin, myricetin, and quercetin were 0.482, 0.517, and 0.394 mg/g DW, respectively, and the antioxidant activity was enhanced to 83%. The optimized extract showed more distinct anticancer activity against HeLa cancer cells in a concentration of 67.2 µg/mL (P < 0.01) without toxicity to normal cells. Conclusions: The results indicated that the pharmaceutical quality of curry leaves could be improved significantly by optimizing the extraction process using response surface methodology. [ABSTRACT FROM AUTHOR]

Highlights: [•] UAE is an effective method for annatto colour extraction in compare to conventional extraction methods. [•] In the optimum conditions, the absorbance value and the extraction yield were obtained 0.865% and 6.35%, respectively. [•] ASE extracted by UAE showed more antioxidant activity than ASE extracted by conventional method. [Copyright &y& Elsevier]

Abstract: Ultrasound (US) was used to facilitate dead-end microfiltration (MF) of grape pomace (GP) extracts. The effects of ultrasonic power, sonication cycle time and ultrasonic probe height on filtration behaviour were investigated. Ultrasonic irradiation had a strong impact on the MF processes, especially with high output power and continuous mode. A comparative study of US-assisted and stirred MF was performed. The energy consumption and liquid flux enhancement of the two filtration systems were compared. Under the same dissipation power, the flux enhancement is much higher for the US-assisted MF. A correlation equation for predicting permeate flux was derived from resistance-in-series model. The flux predictions were confirmed with the experimental results. Finally, the characteristics of permeate after US-assisted and stirred filtration were evaluated. [Copyright &y& Elsevier]

Abstract: This work is focused on the ultrasound-assisted hydrolysis of palm leaves to obtain fermentable sugars using phosphoric acid as catalyst. The effects of phosphoric acid concentration (5.0–20wt%) and temperature (30–65°C) on the hydrolysis and kinetic parameters were evaluated. The maximum amounts of fermentable sugar obtained were 0.55 and 0.59g sugarg−1 dry material, leading to maximum efficiencies of hydrolysis of 68.8 and 74.0% in the absence and presence of ultrasound, respectively. The kinetic parameters obtained from the overall reaction curves showed that the ultrasound intensified the releasing of fermentable sugars in the period of constant reaction rate, since 51% of total fermentable sugar was released in this period in comparison with 45% in the absence. [Copyright &y& Elsevier]

A facile synthesis of hitherto unreported benzofuran-2-yl(9-methyl-9 H-carbazol-3-yl)methanones ( 3a- l) is described. The synthesis mainly relies on the ultrasound-assisted Rap-Stoermer reaction of 3-chloroacetyl-9-methyl-9 H-carbazole ( 1) with a variety of salicylaldehydes, as well as 2-hydroxy-1-naphthaldehyde ( 2) in CHCN, with the presence of PEG-400 as a catalyst. This procedure offers easy access to benzofuran-2-yl(carbazolyl)methanone derivatives in a short reaction time and the products are achieved in good yields. [ABSTRACT FROM AUTHOR]

Abstract: We report a convenient, neutral, and facile methodology for the synthesis of aromatic 1,2-diketones from the corresponding oximinoketones in the presence of I2/SDS/water system under ultrasound-assisted conditions. Furthermore, a series of compounds were synthesized and characterized by melting point, IR, NMR, MS, and elemental analysis. Utilization of easy reaction conditions, very high to excellent yields, and short reaction times makes this manipulation potentially very useful. [Copyright &y& Elsevier]