Ograniczanie wyników
Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 319

Liczba wyników na stronie
first rewind previous Strona / 16 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  extraction
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 16 next fast forward last
PL
W niniejszym rozdziale podjęto próbę opisu wpływu rewolucji łupkowej na rynek tzw. Natural Gas Liquids (etan, propan, butan, izobutan, pentan). Opisano szanse i wyzwania stojące przed rozwojem petrochemii opartej na krakerach parowych w Europie. Omówiono stosunek cen ropy naftowej do gazu ziemnego jako miarę względnej wartości węglowodorów w postaci ciekłej (np. ropy naftowej) i węglowodorów w postaci gazowej (np. gazu ziemnego). Rewolucja łupkowa dokonała znacznego postępu w technologiach, które obejmują wykorzystanie wody lub cieczy pod wysokim ciśnieniem do ekstrakcji gazu, kondensatu czy ropy naftowej. W rezultacie produkcja NGL – ciekłych pochodnych gazu ziemnego, stale rośnie. Wyzwaniem związanym z NGL jest to, że są one droższe w obsłudze, przechowywaniu czy transporcie w porównaniu z produktami rafinowanymi, ponieważ NGL wymagają wysokiego ciśnienia lub niskiej temperatury, aby były utrzymywane w stanie ciekłym, gotowe do wysyłki i przetworzenia. NGL są również wysoce łatwopalne i wymagają użycia specjalistycznej logistyki jak: cystern-ciężarówek, statków i zbiorników magazynowych. Polityka energetyczna i przewidywane odejście od węglowodorów powinno spowodować, że zapotrzebowanie na duże jednostki olefinowe i poliolefinowe zmniejszy się w ciągu najbliższych 20–25 lat z powodu przejścia na recykling mechaniczny i chemiczny plastików. Należy brać pod uwagę, że surowcami do produkcji polimerów staną się odpady z tworzyw sztucznych a nie jak dotychczas etylen (etan) i propylen (propan). Unia Europejska wprowadzając Europejski Zielony Ład pokazuje ambitny plany bycia klimatycznie neutralną do 2050 roku. Osiągnięcie tego celu będzie możliwe tylko dzięki nowym, opracowanym przez branżę petrochemiczną rozwiązaniom w zakresie gospodarki klimatycznej i cyrkularnej. Przemysł chemiczny jest niezbędny dla silnej i zrównoważonej gospodarki Europy przyszłości, ponieważ chemikalia są obecne w prawie każdym strategicznym łańcuchu wartości.
EN
The chapter attempts to describe the impact of the shale revolution on the market of the so-called Natural Gas Liquids (ethane, propane, butane, isobutane, pentane). The opportunities and challenges facing the development of steam cracker-based petrochemistry in Europe are described. The ratio of crude oil prices to natural gas is discussed as a measure of the relative value of hydrocarbons in liquid form (e.g. crude oil) and hydrocarbons in gaseous form (e.g. natural gas). The shale revolution has made significant advances in technologies that include the use of high-pressure water or liquids to extract gas, condensate or crude oil. As a result, the production of NGL – liquid derivatives of natural gas – is constantly increasing. The challenge with NGLs is that they are more expensive to handle, store or transport compared to refined products because NGLs require high pressure or low temperature to be kept liquid, ready for shipment and processing. NGLs are also highly flammable and require the use of specialized logistics such as tank-trucks, ships and storage tanks. Energy policy and the anticipated move away from hydrocarbons should reduce the demand for large olefin and polyolefin units over the next 20–25 years due to the shift to mechanical and chemical recycling of plastics. It should be taken into account that the raw materials for the production of polymers will be plastic waste and not ethylene (ethane) and propylene (propane) as before. By introducing the European Green Deal, the European Union shows ambitious plans to be climate neutral by 2050. Achieving this goal will only be possible thanks to new solutions developed by the petrochemical industry in the field of climate and circular economy. The chemical industry is essential for a strong and sustainable European economy of the future, as chemicals are present in almost every strategic value chain.
PL
Przeprowadzono badania procesu przyśpieszonej ekstrakcji rozpuszczalnikiem olejku eterycznego z goździków, w zakresie temp. 40-120°C, używając rozpuszczalników o różnej polarności (etanol, izopropanol, chloroform, dichlorometan). Wyznaczono wydajności ekstrakcji trzech dostępnych w handlu surowców oraz określono skład i czystość uzyskanych olejków za pomocą techniki spektroskopii w podczerwieni. Zbadano również wpływ starzenia goździków na zawartość i skład olejków. Ponadto porównano otrzymane olejki z produktami komercyjnymi. Wykazano, że największe wydajności ekstrakcji otrzymano, stosując rozpuszczalniki polarne i wyższe temperatury procesu (ok. 31% dla izopropanolu w 120°C), przy czym wraz ze wzrostem temperatury obserwowano wzrost zawartości zanieczyszczeń pochodzących z rozkładu celulozy. Najlepsze wyniki pod kątem wydajności ekstrakcji olejków z goździków i jego składu zapewniało stosowanie silnie polarnych rozpuszczalników i temp. 80°C.
EN
The process of accelerated solvent extn. of essential oil from cloves was tested in the temp. range of 40-120°C using solvents of various polarities (EtOH, iso-PrOH, CHCl₃ , CH₂ Cl₂ ). The extn. efficiency, as well as the qual. compn. and purity of oils obtained from 3 com. available raw materials were detd. using the IR technique. The effect of clove aging on the content and compn. of oils was also examined. The obtained oils were compared with com. products. The best results were provided by the use of highly polar solvents and a temp. of 80°C.
EN
The development of construction aggregate extraction in the years 1993 - 2022 is presented. In order to estimate the volume of production of aggregates, econometric dependencies of aggregate extraction on three macroeconomic indicators, published on a monthly basis by the GUS, i.e.: GDP, cement consumption and the business index in the construction industry. The significant econometric relationships found for the analysed variables allow for the development of forecasts of aggregate extraction, which is an important advantage of the analysis.
PL
Przedstawiono rozwój wydobycia kruszyw budowlanych w latach 1993 - 2022. W celu oszacowania wielkości produkcji kruszyw opracowano ekonometryczne zależności wydobycia kruszyw od trzech makroekonomicznych wskaźników, publikowanych w okresach miesięcznych przez GUS, takich jak: PKB; zużycie cementu i wskaźnik koniunktury w budownictwie. Stwierdzone istotne zależności ekonometryczne w przypadku analizowanych zmiennych pozwalają na opracowanie prognoz wydobycia kruszyw, co jest ważną zaletą analizy.
EN
This study aimed to determine the quantity and quality of dissolved organic carbon (DOC) released from sewage sludge-derived biochar and digestion-derived biochar under different extraction conditions (deionised water, hot water, 0.1 mol·L-1 NaOH) using TOC analyser, UV-vis spectroscopy. Biochars were produced through the pyrolysis process at temperatures of 400, 500, 600, and 800°C. The objective of this article was to examine the influence of diverse extraction solutions on the amount of dissolved organic carbon (BDOC) released from biochars and to delineate alterations in the composition and characteristics of DOC contingent on the extraction parameters. The f indings demonstrated that elevated pyrolysis temperatures resulted in a notable reduction in DOC concentration, with fractions extracted using NaOH exhibiting the highest DOC concentrations. SUVA254 analysis and the E2/E3 ratio indicated that biochars produced at higher temperatures contained a greater proportion of aromatic and hydrophobic substances. These results indicate that pyrolysis temperature, feedstock type and extraction conditions are of significant importance for the properties of DOC in biochar. This has important implications for their potential applications in soil management and carbon sequestration strategies.
PL
W dzisiejszych czasach wzrasta zainteresowanie związkami, jakimi są przeciwutleniacze, ze względu na ich biologiczną aktywność – zdolność antyoksydacyjną. Znajomość zawartości substancji aktywnych w różnych produktach jest niezwykle istotna w dbaniu o swoje zdrowie i prewencje chorób. W pracy poświęcono uwagę ekstraktom z cytryny, imbiru, rożeńca górskiego, brzozy oraz mięty. Pomiaru ilości antyoksydantów dokonano z użyciem trzech metod: Folina-Ciocalteu, DDPH i ABTS. Celem było oznaczenie zawartości antyoksydantów oraz porównanie wyżej wymienionych metod. Najgorsze właściwości antyoksydacyjne wykazała cytryna, natomiast najlepsze efekty posiadał korzeń różeńca górskiego.
EN
Nowadays, there is a growing interest in antioxidant compounds because of their biological activity – antioxidant capacity. Knowledge of the content of active substances in various products is extremely important in caring for one’s health and preventing disease. In this study, attention was paid to extracts from lemon, ginger, mountain ash, birch, and mint. Antioxidant amounts were measured using three methods: Folin-Ciocalteu, DDPH, and ABTS. The aim was to determine the antioxidant content and to compare the aforementioned methods. Lemon showed the worst antioxidant properties, while Rhodiola rosea root had the best results.
EN
Flotation tailings originating from copper ore processing were evaluated in terms of chemical and mineralogical features, leaching, and resource potential. The results demonstrated that flotation tailings show varying degrees of the leachability of elements when exposed to different pH conditions (2–13); the Zn, Cu and Co leachabilities decrease as pH increases, whereas Mo, Ag and Sb revealed U-shaped leaching trend as a function of pH. Flotation tailings were found to be fairly reactive when exposed to water leaching and rainfall conditions. The environmental risk analysis demonstrated Zn to be the most susceptible element to liberation from the flotation tailings studied. Recovery tests demonstrated sulfuric acid to be slightly more efficient extracting agent as compared to citric acid. Hybrid approach to metal recovery was rather unsuitable for studied tailings due to lower extraction yield (not exceeding 20%) as compared to chemical treatment (not exceeding 40%).
EN
This study aims to optimize chitin extraction conditions by reducing water and chemical consumption using a twolevel factorial design approach. Two variables were studied for the demineralization process: the volume of hydrochloric acid (400 to 500 mL) and the demineralization time (1 to 1.5 hours) at room temperature. For deproteinization, the variables examined were NaOH concentration (0.6 to 1 mol/L) and deproteinization time (1 to 1.5 hours) at 70–80 °C. The ash and protein contents were measured to evaluate the efficiency of the demineralization and deproteinization processes, respectively. Minitab 18 software was used for the experimental design. The results showed that the best conditions for extracting high-quality chitin are a demineralization time of 1 hour, an HCl volume of 500 mL, a NaOH concentration of 1 M, and a deproteinization time of 1 hour. These optimal conditions reduce the amount of water, time, and chemicals required for chitin extraction. Compared to previous studies, we significantly reduced the amount of water and chemicals as well as the extraction duration. These results are innovative as they offer a more efficient and sustainable solution for chitin extraction, thus filling a gap in current research by proposing an optimized method. By providing these new data and demonstrating their effectiveness, our research makes a significant contribution to improving chitin extraction techniques, addressing an unmet need in the industrial field.
EN
The goal of this study is to use a simple approach to synthesize pectin from grapefruit peel, an agricultural waste common in tropical regions. Additionally, the study employed optimization techniques to identify the ideal conditions for the maximum extraction efficiency while also determining the importance of studying factors. Besides, extracted pectin characteristics are also presented in this research. Under several analysis, some chemical groups for pectin were presented in extracted pectin by Fourier transform infrared spectroscopy analysis (FTIR). For instance, C-H methyl groups at the peak 1442 cm-1; methyl ester groups C=O appears at the wavelength 1747 cm-1 and aliphatic C-H groups and hydroxyl groups. Furthermore, under three major conditions acid (%); temperature and time extraction, an optimization study was conducted to figure out the optimal conditions for pectin extraction efficiency. Under optimal conditions acid 10%; 77.5 °C and 80 mins is the favorable condition for obtaining pectin extraction efficiency. Basically, this study is the first one extracting pectin from rosy-pulp pomelo peel by sulfuric acid-ethanol precipitation method. This is a preliminary that lays the foundation for purifying extracted pectin from rosy-pulp pomelo, also solving this agricultural waste bring higher economic values.
EN
In Morocco, the Tamaricaceae family is represented by six species belonging to the Tamarix genus. including Tamarix africana which is utilized in traditional medicine to treat various ailments. This study aims to compare and evaluate the total polyphenol and flavonoid contents, as well as the antioxidant and antibacterial activity of Tamarix africana leaf and flower extracts obtained by Soxhlet extraction using five solvents of increasing polarity. The highest extraction yield was obtained with methanol for the leaves and flowers. Indeed, the results indicate that methanolic extracts contained the highest concentration of polyphenols and flavonoids for both organs (Polyphenols: 101.80 mg GAE/g DW in the leaf extract and 50.55 mg GAE/g DW in the flower extract. Flavonoids: 990.723 µg RE/g DW in the leaf extract and 630.84 µg RE/g DW in the flower extract). The results of antioxidant activity revealed that the aqueous extract of leaves and flowers of T. africana (IC50: 1.89 µg/mL and 3.175 µg/ mL respectively) had higher antioxidant activities than ascorbic acid. Concerning the antibacterial study, Bacillus subtilis showed resistance to the tested extracts. However, for the Citrobacter freundii strain, inhibition zones of 14 mm were recorded by the aqueous extract of flowers. On the other hand, the strong inhibition zones recorded against the Enterococcus faecalis strain, were 13 mm recorded by the leaves methanolic extract. Regarding the MIC, it is 6.25 mg/ml for the two strains. Concerning MBC, the results showed that the extracts are bacteriostatic in nature against Citrobacter freundii and Enterococcus faecalis. Thus, Tamarix africana seems to be a potential source of active molecules that could constitute a new alternative for medical and industrial use.
EN
In recent years, it has been realized that agriculture has become one of the economic sectors with a huge impact on the environment. There-fore, measures have been taken to reduce the negative impact of agricultural production on the environment. The use of biostimulants in agriculture, especially of plant origin, is part of this trend. However, obtaining suitable formulation of biostimulants requires the development of appropriate technologies for their production. Therefore, it was undertaken to investigate the possibility of using gliding arc cold plasma (GA) and low-pressure microwave (MW) discharges to produce water plant extracts with biostimulating potential. An increase in total polyphenol content and antioxidant activity was observed, indicating the high potential of using low-pressure microwave discharge to produce effective plant biostimulants. Also, low-pressure microwave discharge improved the extraction of elements such as Ca, K and Fe.
PL
W ostatnich latach zdano sobie sprawę, że rolnictwo stało się jednym z sektorów gospodarki o ogromnym wpływie na środowisko. W związku z tym podjęto działania mające na celu zmniejszenie negatywnego wpływu produkcji rolnej na środowisko. Wykorzystanie biostymulatorów w rolnictwie, zwłaszcza pochodzenia roślinnego, jest częścią tego trendu. Uzyskanie odpowiedniej formulacji biostymulatorów wymaga jednak opracowania odpowiednich technologii ich produkcji. W związku z tym podjęto się zbadania możliwości wykorzystania zimnej plazmy (GA) i niskociśnieniowych wyładowań mikrofalowych (MW) do produkcji wodnych ekstraktów roślinnych o potencjale biostymulującym. Zaobserwowano wzrost całkowitej zawartości polifenoli i aktywności przeciwutleniającej, co wskazuje na wysoki potencjał wykorzystania niskociśnieniowych wyładowań mikrofalowych do produkcji skutecznych biostymulatorów roślinnych. Ponadto, niskociśnieniowe wyładowanie mikrofalowe poprawiło ekstrakcję pierwiastków takich jak Ca, K i Fe.
EN
The changing climate, causing more frequent abiotic stresses, has generated interest in products that can mitigate the negative impacts of these changes. One such group of preparations includes plant extracts with biostimulant potential, produced using various methods and techniques, including cold plasma and low-pressure microwave discharge. However, there is limited research on how production methods and techniques affect the physical properties of biostimulants, such as density, viscosity, and surface tension. This study aimed to evaluate the impact of the manufacturing process on these properties. The biostimulant was produced via hot water extraction using either cold plasma or low-pressure microwave discharge. Results showed that neither method reduced the surface tension of the biostimulants, but they significantly influenced the viscosity and density. Given these changes in physical properties, further research on droplet spectrum and plant coverage during application is necessary to determine the optimal technical parameters for effective spraying.
PL
Zmieniający się klimat powodujący coraz częściej występowanie stresów abiotycznych wpłyną na zwiększenie zainteresowania preparatami mogącymi niwelować negatywne skutki tych zmian. Jednymi z takich preparatów są ekstrakty roślinne o potencjale biostymulującym wytwarzane rożnymi metodami i technikami z wykorzystaniem m.in. zimnej plazmy czy niskociśnieniowego wyładowania mikrofalowego. Jest jednak niewiele doniesień dotyczących wpływu metody czy techniki wytwarzania biostymulatorów na ich właściwości fizyczne takie jak gęstość, lepkość i napięcie powierzchniowe. Dlatego też w pracy podjęto się oceny wpływu procesu wytwarzania biostymulatora na ww. cechy. Biostymulator wytwarzano metodą ekstrakcji wodnej na gorąco z zastosowaniem zimnej plazmy lub niskociśnieniowego wyładowania mikrofalowego. Badania wykazały, że zastosowanie w procesie wytwarzania zimnej plazmy lub niskociśnieniowego wyładowania mikrofalowego nie wpłynęło na zmniejszenie napięcia powierzchniowego biostymulatorów, ale wpłynęło istotnie na lepkość oraz gęstość wytwarzanych biostymulatorów. W związku ze zmianą właściwości fizycznych takich jak lepkość i gęstość w wyniku zastosowania zimnej plazmy lub niskociśnieniowego wyładowania mikrofalowego należy przeprowadzić dalsze badania dotyczące spektrum kropel oraz stopnia pokrycia roślin podczas zabiegu w celu doboru odpowiednich parametrów technicznych warunkujących jak najlepsze wykonanie oprysku.
12
Content available remote Badanie procesu ekstrakcji polisacharydów z Pleurotus geesteranus
PL
Sproszkowany Pleurotus geesteranus poddano ekstrakcji ultradźwiękowej z użyciem wody w celu odzyskania polisacharydów. Wpływ stosunku masy ciała stałego do masy cieczy (stosunek ciało stałe-ciecz), pH, temperatury i czasu działania ultradźwięków na wydajność ekstrakcji badano za pomocą testu jednoczynnikowego i ortogonalnego. Czynniki zostały uporządkowane wg malejącego wpływu na wydajność procesu w szeregu: temperatura > stosunek ciało stałe-ciecz > pH > czas. Optymalne warunki procesu to: stosunek ciało stałe-ciecz 1:20, pH 10, temp. 70°C i czas działania ultradźwięków 5 min. Niepewność powtarzalności wyników wynosiła 0,01301%, 0,0098% i 0,01386%. Współczynnik ekstrakcji polisacharydów z Pleurotus geesteranus wynosił ok. 0,012%.
EN
Pleurotus geesteranus powder was processed by ultrasonic extn. with water to recover polysaccharides. The effects of solid-liq. ratio, pH, temp. and ultrasonic time on the extn. efficiency were studied by single factor and orthogonal tests. The factors were ordered according of decreasing efficiency in series: temp. > solid-liq. ratio > pH > time. The optimum process conditions were: solid-liq. ratio 1:20, pH 10, temp. 70°C, and ultrasonic time 5 min. The repeatability uncertainties of this protocol were 0.01301%, 0.0098%, and 0.01386%. The extn. rate of polysaccharides from Pleurotus geesteranus was about 0.012%.
EN
Addition of organic acids to dilute hydrochloric acid solution can improve the extraction of rare earth elements by single cationic extractants. However, the correlation between the chemical structure of organic acids and the extraction of REEs as well as the variation in equilibrium pH has not been elucidated. In this study, we investigated the extraction of Tb(III) from dilute HCl solutions containing an organic acid like formic, lactic, fumaric, or maleic acid. As extractants, single Cyanex 272, a mixture of Cyanex 272 and Alamine 336 (Ala336-Cy272), and an ionic liquid (ALi-Cy272) synthesized by Cyanex 272 and Aliquat 336 were used. The speciation of Tb(III) in dilute HCl solutions containing organic acids was analyzed. In extraction of Tb(III), organic acids showed two roles as complexing and buffering agent, which depended on the chemical structure of the acids. There was some difference in the extraction of Tb(III) between single Cyanex 272 and ionic liquid, ALi-Cy272. During extraction with ALi-Cy272, formic and lactic acid negatively affected the extraction of Tb(III). The fact that the chemical structure of organic acids affected the extraction of Tb(III) from dilute HCl solution by the studied extractants can provide important information on the selection of suitable extraction systems.
EN
The extraction of light rare earths (Pr and Nd) from chloride medium was investigated using a mixture of di(2-ethylhexyl) phosphoric acid (P204) and bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanex272) in sulfonated kerosene. The P204+Cyanex272 system exerted a synergistic effect on the separation of light rare earths, and the separation coefficient was higher than when P204 and Cyanex272 were used as extractants alone. The separation coefficient of Pr and Nd in the extraction system reached 1.75 when the pH of the aqueous phase material solution was approximately 2.5, and 1.5 mol/L hydrochloric acid as a stripping agent effectively eluted the rare earth ions in the loaded organic phase. Combining the slope method, infrared spectroscopy, and nuclear magnetic resonance spectroscopy, we explored the mechanism of the extracted Nd and Pr into the organic phase complex, and finally entered the organic phase with Re(HA2)2B. The P-O-H bond and P=O bond in the extractant P204 and Cyanex272 formed a coordination bond with Re3+. Therefore, this extraction method also provides a reference for a more environmentally friendly and efficient procedure for separation and purification of light rare earth elements Pr and Nd.
EN
Every year, the production of industrial phosphoric acid generates more than 100 Tg of phosphogypsum (PG), leading to significant environmental damage and the occupation of a vast amount of land space. The urgent need to explore applications for PG has become increasingly apparent. However, impurities such as organic substances, slime, phosphorite, and SiO2 reduce the whiteness of PG, making it difficult to utilize for high-value applications. To address this issue, this study employed a two-stage flotation process to remove the majority of impurities, including SiO2, organic substances, and fine slime adhered to the surface of PG particles. The raw PG sample was first sieved to remove some SiO2 particles. After flotation, sulfuric acid and tributyl phosphate were introduced to decompose the PG particles and remove the impurities wrapped inside. Following this flotation combined extraction process, the whiteness of the PG sample improved from 54.1% to 92.9%, meeting the requirements for building walls and filters.
PL
Neonikotynoidy to insektycydy powszechnie występujące w środowisku oraz w żywności. W artykule opisano podstawowe metody ich ekstrakcji z różnych matryc oraz identyfikacji i analizy ilościowej przy użyciu techniki LC-MS/MS. Omówione zostały także podstawowe problemy w analizie obejmujące niskie stężenia związków, wpływ matrycy na wyniki, a także ograniczenia związane z jonizacją tych substancji.
EN
Neonicotinoids are insecticides commonly detected in the environment and in food samples. The article describes the most common methods of their extraction, identification and quantitative analysis using the LC-MS/MS approach. Difficulties in analytical procedures, including very low concentrations of analytes, matrix effects and limited ionisation in ESI-MS are also briefly discussed.
17
Content available remote Improving the technology of obtaining humic substances from peat
EN
The study of the extraction of humic substances from peat is considered in the work. During the studies of various mode parameters of extraction, the optimal one was determined, which obtained a higher yield of humic substances. For decades, the arguments of plant growers about which forms of fertilizers are more useful for soil fertility and more effective for plants - organic or mineral - have not subsided. Each of these types has its own disadvantages and advantages, and as it turned out later, it is possible to keep the soil healthy and get the maximum benefit only with a competent combination of them.
EN
The olive mill wastewater, effluents from the trituration of olives, are treated in most Mediterranean countries by natural evaporation. However, this method of treatment is a source of air and soil pollution by the generation of solid waste, called olive mill waste cake. This work focused on extracting of vegetable oil from this by-product for biodiesel production by transesterification. The extraction took place with a Soxhlet extractor, using hexane as solvent. The vegetable oil and biodiesel were characterized by measuring the physicochemical parameters that identify them according to AFNOR standards. The extraction results show that the oil yield is 21.28%. The oil obtained is characterized by density, water and ash content, acidity, saponification, peroxide and ester. The yield of the oil esterification reaction is 86.41% or about 185 Kg of biodiesel/ton of olive mill waste cake, and in terms of energy 2783.7 MJ or 2 GW.t-1. The biodiesel produced is comparable to petroleum diesel according to EN 14214, 2013.
EN
It is necessary to find innovative ways to improve the environmental performance of production processes and products. The technology of extracting valuable components from raw materials of plant origin is often used in technological processes of the food, pharmaceutical, chemical and other industries. Extraction is the most energy intensive step. The factors contributing to the extraction of humic acids from plant substrates under the action of electric discharge were studied. The purpose of the work was to study the efficiency of humic acids extraction from the biosubstrate under the action of electric discharges. The physical experiment showed that the main factor influencing the intensity of extraction is the degree of grinding of the solid phase of the biosubstrate-water suspension. The efficiency of electric discharge grinding depends on the pressure amplitude at the distance of the inner radius of the chamber and the number of discharge pulses. It was established that the number of chemical reagents (alkalis), usually used in the process of extracting humic acids from peat, can be reduced many times due to the appearance of radicals and peroxide compounds in the peat-water suspension resulting from the action of an electric discharge. The prospects of the non-thermal electric discharge method of intensification of the extraction of humic acids from biosubstrates were determined.
EN
The study was aimed to evaluate the impact of extraction solvent on the phenolic content, total flavonoids content, and the antioxidant activities of acetonic, methanolic, and aqueous extracts of two lichen species: Evernia prunastri and Ramalina lacera collected from trunks of Argania spinosa using the ultrasound assistance extraction. Various in vitro antioxidant assays were utilized such as 2,2-diphenly-picryly-hydroxyl free radical (DPPH) assay, and ferric reducing antioxidant power (FRAP) assay. All tested samples exhibited a good antioxidant activity, for the DPPH assay, the inhibition percentage ranged from 85±0.2% to 27±0.01%, the phenolic content ranged from 13.17±0.5 mgGAE/g DW to 3.31±0.3 mgGAW/g DW, and flavonoids ranged from 5.84±0.03 mgRE/g DW to 0.01±0.03 mgRE/g DW. This study demonstrates that the extraction solvent has a significant influence on lichens phenolic compounds and on their antioxidant activity, also showed that flavonoids contents are significantly correlated to antioxidant activity of studies lichens; moreover, it shows that ultrasound extraction in a good method to extract the lichens compound. This study suggests that lichens Ramalina lacera and Evernia prunastri could be utilized as natural antioxidant source.
first rewind previous Strona / 16 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.