scholarly journals Ultrasound and shacking-assisted water-leaching of anions and cations from fly ash

2016 ◽  
Vol 81 (7) ◽  
pp. 813-827 ◽  
Author(s):  
Marjetka Savic-Bisercic ◽  
Lato Pezo ◽  
Ivana Sredovic-Ignjatovic ◽  
Ljubisa Ignjatovic ◽  
Andrija Savic ◽  
...  
Keyword(s):  
Fly Ash ◽  
Environmental Conditions ◽  
Ph Value ◽  
Coal Fly Ash ◽  
Principal Component ◽  
Absorption Spectrometry ◽  
Extraction Process ◽  
Ultrasound Assisted Extraction ◽  
Water Leaching ◽  
Assisted Extraction

Two mechanical extraction techniques were used for the extraction of environmentaly interesting elements from coal fly ash: shaking, in which the extraction process lasted from 6 to 24 hours, and ultrasonic sonication during 15 to 60 minutes, with water as extractant. The concentration of anions in fly ash extracts were determined by ion chromatography, while atomic absorption spectrometry was used for determination of: As, Pb, Cd, Ni, Cr, Zn, Cu, Fe, Mn and Al. The ultrasonic sonication yielded slightly higher amounts of extracted anions and Pb, Al, Mn and Fe, while shaking-assisted extraction was more efficient for the Cr, As, Zn and Ni ions. The changes in pH value, particle size distribution in colloid, zeta potential and conductivity during ultrasound-assisted extraction were measured in order to explain changes on the surface of fly ash particles in contact with water and different processes (adsorption, ion exchange, flocculation) that occur in environmental conditions. Principal Component Analysis were used for assessing the effect of observed process parameters. Essential from a practical point of view is a quantitative evaluation of these elements leachable from coal fly ash to surface waters in environmental conditions and contamination of the environment.

scholarly journals Aqueous extraction of anions from coal and fly ash followed by ion-chromatographic determination

2016 ◽  
Vol 81 (12) ◽  
pp. 1441-1453
Author(s):  
Aleksandra Tasic ◽  
Ivana Sredovic-Ignjatovic ◽  
Ljubisa Ignjatovic ◽  
Danijel Djuranovic ◽  
Malisa Antic
Keyword(s):  
Fly Ash ◽  
Ph Value ◽  
Chromatographic Determination ◽  
Aqueous Extraction ◽  
Microwave Assisted Extraction ◽  
Ultrasound Assisted Extraction ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Coal Particles ◽  
Ultrasound Assisted

Three different techniques were applied for the aqueous extraction of anions from coal and fly ash: rotary mixer- and ultrasonic-assisted extraction with different duration time, and microwave-assisted extraction at different temperatures. Validation showed that the ion-chromatographic method was suitable for the analysis of anions in coal and fly ash extracts. The variations in the amounts of anions using different extraction times during rotary-assisted extraction were minimal for all investigated anions. The efficiency of ultrasound-assisted extraction of anions from coal depended on the sonication time and was highest at 30 min. The ultrasound-assisted extraction was less efficient for the extraction of anions from fly ash than rotary-assisted extraction. Increase of temperature in the microwave-assisted extraction had a positive effect on the amounts of all anions extracted from coal and sulphate from fly ash, while the amounts of fluoride and chloride in fly ash extracts decreased. The microwave-assisted extraction of coal at 150?C was compared with standard ASTM methods, and results were in good agreement only for chloride. Changes in the pH value and conductivity during ultrasound-assisted extraction were measured in order to explain changes on the surface of coal particles in contact with water and different processes that occur under environmental conditions.

scholarly journals Bioactive Phenolic Metabolites from Adriatic Brown Algae Dictyota dichotoma and Padina pavonica (Dictyotaceae)

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1187
Author(s):  
Ivana Generalić Mekinić ◽  
Vida Šimat ◽  
Viktorija Botić ◽  
Anita Crnjac ◽  
Marina Smoljo ◽  
...  
Keyword(s):  
Total Phenolics ◽  
Antioxidant Activities ◽  
Principal Component ◽  
Ultrasound Assisted Extraction ◽  
Antioxidant Power ◽  
Dictyota Dichotoma ◽  
Assisted Extraction ◽  
Sample Data ◽  
Ferric Reducing Antioxidant Power ◽  
The Individual

In this study, the influences of temperature (20, 40 and 60 °C) and extraction solvents (water, ethanol) on the ultrasound-assisted extraction of phenolics from the Adriatic macroalgae Dictyota dichotoma and Padina pavonica were studied. The extracts were analysed for major phenolic sub-groups (total phenolics, flavonoids and tannins) using spectrometric methods, while the individual phenolics were detected by HPLC. The antioxidant activities were evaluated using three methods: Ferric Reducing/Antioxidant Power (FRAP), scavenging of the stabile 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and Oxygen Radical Antioxidant Capacity (ORAC). The aim of the study was also to find the connection between the chemical composition of the extracts and their biological activity. Therefore, principal component analysis (PCA), which permits simple representation of different sample data and better visualisation of their correlations, was used. Higher extraction yields of the total phenolics, flavonoids and tannins were obtained using an alcoholic solvent, while a general conclusion about the applied temperature was not established. These extracts also showed good antioxidant activity, especially D. dichotoma extracts, with high reducing capacity (690–792 mM TE) and ORAC values (38.7–40.8 mM TE in 400-fold diluted extracts). The PCA pointed out the significant influence of flavonoids and tannins on the investigated properties. The results of this investigation could be interesting for future studies dealing with the application of these two algae in foods, cosmetics and pharmaceuticals.

Research on Detecting Tris-(2,3-dibromopropyl)-Phosphate in Textiles with the HPLC/DAD Method

2012 ◽  
Vol 441 ◽  
pp. 640-644
Author(s):  
Ke Jie Fu ◽  
Li Sheng Yang ◽  
Chang Sheng Feng ◽  
Liang Chen
Keyword(s):  
Limit Of Detection ◽  
Extraction Process ◽  
Ultrasound Assisted Extraction ◽  
Routine Testing ◽  
Assisted Extraction ◽  
Ultrasound Assisted ◽  
Pre Treatment ◽  
Finishing Agent ◽  
Detecting Method ◽  
Precision Test

A detecting method for toxic flame retardant finishing agent tris-(2,3-dibromopropyl) -phosphate (TRIS for short) in textiles was studied. In the method, an acetonitrile ultrasound-assisted extraction process was included in sample pre-treatment, and HPLC/DAD was used in the separation and identification of extractives. After that, the conditions of pre-treatment and chromatograph were optimized. The results showed that the limit of detection (LOD) by this method (S/N10) is 1.0 mg/kg, its recovery ranged from 78.1% to 98.4%, and RSD of the precision test is 3.2%, of which all met the requirements for routine testing.

Optimization of Ultrasound-Assisted Extraction of Cr, Cu, Zn, Cd, and Pb from Sediment, Followed by FAAS and GFAAS Analysis

2016 ◽  
Vol 99 (1) ◽  
pp. 252-259 ◽  
Author(s):  
Aparecida M S Mimura ◽  
Marcone A L Oliveira ◽  
Virginia S T Ciminelli ◽  
Julio C J Silva
Keyword(s):  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Matrix Effects ◽  
Graphite Furnace ◽  
Absorption Spectrometry ◽  
Ultrasound Assisted Extraction ◽  
Flame Atomic Absorption ◽  
Assisted Extraction ◽  
Graphite Furnace Atomic Absorption ◽  
Standard Additions

Abstract An ultrasound method for simultaneous extraction of Cr, Cu, Zn, Cd, and Pb from sediment, and determination by flame atomic absorption spectrometry (FAAS) and graphite furnace atomic absorption spectrometry (GFAAS) was proposed. The experimental results obtained using analytical curves and the method of standard additions agreed at a confidence level of 95% for all the analytes, as determined by FAAS and GFAAS, indicating no significant matrix effects. Recoveries ranged from 80.1 to 93.7% (certified reference material) and from 89 to 107% (spike tests). The LOD and LOQ results from the method were consistent with the techniques used (FAAS and GFAAS), with high analytical throughput. The proposed method was then used to determine Cr, Cu, Zn, Cd, and Pb in river sediment samples from Rio Doce, Minas Gerais, Brazil. The results indicated levels below those permitted by Brazilian legislation for all the analytes, with the exception of Cr.

scholarly journals Volarization of valuable compound from watermelon by-product using ultrasound-assisted extraction

Food Research ◽  
2020 ◽  
Vol 4 (6) ◽  
pp. 1995-2002
Author(s):  
W.Y.C. Lim ◽  
N.L. Yusof ◽  
Ismail-Fitry M.R. ◽  
N. Suleiman
Keyword(s):  
Citric Acid ◽  
Acid Content ◽  
Galacturonic Acid ◽  
Value Added ◽  
Extraction Process ◽  
Ultrasound Assisted Extraction ◽  
Pectin Content ◽  
Watermelon Rind ◽  
Assisted Extraction ◽  
Confectionery Products

The aim of this study was to develop an efficient, reliable, and sustainable technology for the recovery of value-added compounds from by-product, in this case, is watermelon rinds. The properties of the watermelon rinds obtained from innovative ultrasoundassisted extraction (UAE) were evaluated. In regard to this, the pectin content, degree of esterification, and galacturonic acid content of the watermelon rind extracts were determined in order to verify the efficiency of the UAE. Initially, the UAE were conducted using two types of acid: citric and hydrochloric. The highest pectin content was obtained using citric acid. Additional UAE was then performed with citric acid at 50, 60, or 70°C for 10, 20, or 30 mins. Both UAE temperature and time significantly influenced the pectin extracts and galacturonic acid. The best findings for a high galacturonic acid content (47.41%) when the watermelon rinds were extracts at 70°C for 20 mins. According to the findings, the extraction process lasted 10 or 20 mins at all temperatures was mainly high-methoxyl pectin, which can form gels under acidic conditions. This suggests that pectins derived from watermelon rinds using UAE may be especially useful as an additive in some confectionery products.

scholarly journals Removal of Phenol from Aqueous Solution by Adsorption on to Coal Fly Ash

1996 ◽  
Vol 13 (6) ◽  
pp. 527-536 ◽  
Author(s):  
L.J. Alemany ◽  
M.C. Jiménez ◽  
M.A. Larrubia ◽  
F. Delgado ◽  
J.M. Blasco
Keyword(s):  
Aqueous Solution ◽  
Fly Ash ◽  
Removal Efficiency ◽  
Ph Value ◽  
Coal Fly Ash ◽  
Solid Wastes ◽  
Power Stations ◽  
Different Temperatures ◽  
Coal Power ◽  
Coal Power Stations

The present work examines the possible use of fly ash, a byproduct of coal power stations, as a means of removing phenol from water, or equivalently, of restricting its movement in solid wastes or soil. Equilibrium experiments were performed to evaluate the removal efficiency of fly ash. The adsorption experiments were undertaken using fly ash treated at three different pH levels and with three different temperatures. The results indicate that although phenol can be removed from water, this depends markedly on the temperature and pH value of the treatment solution employed.

scholarly journals Antioxidant Capacity and Antigenotoxic Effect of Hibiscus sabdariffa L. Extracts Obtained with Ultrasound-Assisted Extraction Process

2020 ◽  
Vol 10 (2) ◽  
pp. 560
Author(s):  
Gregorio Iván Peredo Pozos ◽  
Mario Alberto Ruiz-López ◽  
Juan Francisco Zamora Nátera ◽  
Carlos Álvarez Moya ◽  
Lucia Barrientos Ramírez ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Human Lymphocytes ◽  
Dry Weight ◽  
Extraction Process ◽  
Hibiscus Sabdariffa ◽  
Ultrasound Assisted Extraction ◽  
Solid Ratio ◽  
Assisted Extraction ◽  
Ultrasound Assisted ◽  
Antigenotoxic Effect

Hibiscus sabdariffa (Roselle) is in high demand worldwide due to its beneficial health properties owing to the polyphenols content, mainly in the flower calyx. The objective of this study was to find the best conditions (time and liquid: solid ratio) to extract polyphenols from Roselle using Ultrasound-Assisted Extraction (UAE) (40 kHz, 180 W), with ethanol how solvent; as well as determine the yield of phenols, anthocyanin, flavonoids, tannins, antioxidant activity (DPPH) and antigenotoxic effect (comet assay). A traditional solid-liquid extraction was applied as a reference. Extraction times of 40 and 60 min resulted in the highest polyphenols (13.019 mg GAE/g dry weight (dw)), flavonoids (4.981 CE/g dw), anthocyanins (1.855 mg Cya3GE/g dw), and tannins (0.745 CE/g dw) recoveries and an antioxidant activity (DPPH) of 74.58%. Extracts from white calyces contained similar amounts of phenols and flavonoids, but very little condensed tannins (0.049 CE/g dw) and practically no anthocyanins. Extracts from red and white calyces, showed antigenotoxic activity and repaired capacity of damage caused by mutagens in human lymphocytes.

scholarly journals Technology and Process Design for Phenols Recovery from Industrial Chicory (Chicorium intybus) Leftovers

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2681 ◽  
Author(s):  
Camilla Maria Cova ◽  
Luisa Boffa ◽  
Marco Pistocchi ◽  
Silver Giorgini ◽  
Rafael Luque ◽  
...  
Keyword(s):  
Extraction Process ◽  
Ethanol Solution ◽  
Ultrasound Assisted Extraction ◽  
Mineral Salts ◽  
Primary And Secondary Metabolites ◽  
Assisted Extraction ◽  
Honestly Significant Difference ◽  
Significant Difference ◽  
Tukey Honestly Significant Difference ◽  
Post Hoc

Vegetal leftovers from the agro–food industry represent a huge source of primary and secondary metabolites, vitamin, mineral salts and soluble as well as insoluble fibers. Economic reports on the growth in the polyphenol market have driven us to focus our investigation on chicory (Chicorium intybus L.), which is one of the most popular horticultural plants in the world and a rich source of phenolic compounds. Ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE) and their simultaneous combination, using either ethanol/water or water alone (also sub-critical), have been investigated with the aim of designing a green and efficient extraction process. Higher total-polyphenol yields as well as dramatic reductions in extraction times and solvent consumption have been obtained under these conditions. ANOVA test for analyses of variance followed by the Tukey honestly significant difference (HSD) post-hoc test of multiple comparisons was used in the statistical analysis. MAE experiments performed with sub-critical water, and MW/US experiments with an ethanol solution have shown polyphenol recovery values of up to ~3 g of gallic acid equivalents (GAE) per kg of fresh material in only 15 min, while conventional extraction required 240 min to obtain the same result.

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