86 research outputs found

    Adsorpcijske izoterme i kinetičko modeliranje uklanjanja fenolnih spojeva pomoću aktivnog ugljena, iz otpadnih voda dobivenih pri proizvodnji maslinovog ulja

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    The adsorption of phenolic compounds from olive oil wastewater by commercial activated carbon was studied as a function of adsorbent quantity and temperature. The sorption kinetics and the equilibrium isotherms were evaluated. Under optimum conditions (8 g of activated carbon per 100 mL), the maximum sorption capacity of activated carbon expressed as mg of caff eic acid equivalent per g of activated carbon was 35.8 at 10 °C, 35.4 at 25 °C and 36.1 at 40 °C. The pseudo-second-order model was considered as the most suitable for kinetic results, and Langmuir isotherm was chosen to bett er describe the sorption system. The results confi rmed the effi ciency of activated carbon to remove almost all phenolic compound fractions from olive mill effl uent. The preliminary results obtained will be used in future studies. The carbohydrate fraction of this upgraded residue could be employed to produce bioethanol, and adsorbed phenolic compounds can be recovered and used in different industries.U radu je ispitana ovisnost adsorpcije fenolnih spojeva iz otpadnih voda, dobivenih pri proizvodnji maslinovog ulja, o količini adsorbensa (komercijalni aktivni ugljen) i temperaturi. Proučene su kinetika sorpcije i ravnotežne izoterme. Pri optimalnim uvjetima (8 g aktivnog ugljena na 100 mL) najveća je sposobnost sorpcije, izražena u mg ekvivalenata kafeinske kiseline po g aktivnog ugljena, iznosila 35,8 pri temperaturi od 10 °C, 35,4 pri 25 °C i 36,1 pri 40 °C. Dobivene kinetičke rezultate najbolje je opisao model pseudo drugog reda, dok je za opisivanje sorpcije odabrana Langmuirova izoterma. Rezultati potvrđuju učinkovitost aktivnog ugljena u uklanjanju gotovo svih fenolnih spojeva iz otpadnih voda. Ovi će se preliminarni rezultati upotrijebiti u daljnjim istraživanjima. Ugljikohidrati preostali nakon uklanjanja fenolnih spojeva iz otpadnih voda mogli bi se upotrijebiti za dobivanje bioetanola, a adsorbirani se fenolni spojevi mogu naknadno koristiti u raznim granama industrije

    Small diameter vascular grafts coated with gelatin

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    In the field of tissue engineering, there is an increased demand for small diameter vascular grafts to treat peripheral vascular pathologies and ischemic heart diseases. The limited availability of suitable autogenous veins and the drawbacks related to the use of synthetic materials, such as polyethylene terephthalate (Dacron\uc2\uae) and expanded polytetrafluoroethylene (ePTFE), especially when they are used as substitutes for small diameter vessels, have attracted several investigators turning their attention toward the fabrication of alternative biocompatible grafts. In this study, small diameter tubular grafts (2 mm), made of poly (\ucf\ub5-caprolactone) (PCL) and poly (glycerol sebacate) (PGS) at a ratio of 1:1 (v/v) were obtained by electrospinning. With the aim to reduce water permeability, their surface was modified by dynamic coating of gelatin at 37 \uc2\ub0C for 1 h, followed by UV-irradiation. Thickness, fiber diameters, porosity, mass loss, fluid uptake, water permeability, gelatin release, mechanical properties, cytotoxicity, and hemocompatibility of gelatin-coated electrospun scaffolds (GCS) were studied and compared with uncoated scaffolds (UCS). Scanning electron microscopy (SEM) images showed that the gelatin surface modification did not affect the 3D structure and pore interconnectivity of the scaffolds. A significant decrease in the water permeability was noticed when gelatin was used as coating agent. The results of this study highlighted the importance of a very low cost surface treatment with gelatin to improve the properties of PCL:PGS electrospun grafts. In conclusion, these gelatin-coated prostheses could be considered as a good candidate for vascular replacement in tissue engineering

    Microalgae growth using winery wastewater for energetic and environmental purposes

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    Winery wastewater (WWW), produced by winemaking activities (cleaning, transferring and storage operations), is an aqueous solution containing ethanol, organic acids, sugars, aldehydes, other microbial metabolites, soaps and detergents. Nowadays, innovative wastewater treatment processes are based on bacterial and yeast species while the role of microalgae is still unclear. Arthrospira (Spirulina) platensis and Chlorella vulgaris are unicellular prokaryotic and eukaryotic microorganisms, respectively, which can be easily grown even in non-optimal conditions. Several studies reported that the amount and quality of lipids contained in microalgal cells can differ as an outcome of changes in growth conditions or growth medium characteristics (concentration of carbon, nitrogen, phosphate, iron, etc.). In this study, we investigated the influence of different concentrations of WWW (20, 40 and 60 % v/v of the medium) on the growth and chemical composition of those photosynthetic microorganisms. Microalgae were grown into vertical glass bubblers (250 mL). The biomass concentration was quantified daily by measuring the optical density at 560 and 625 nm for A. platensis and C. vulgaris, respectively. Total Carbon and total Nitrogen concentrations, both in the media (mg/L) and in microalga biomass (g/100g), were monitored by a CHNS-O analyser. In order to quantify the influence of WWW-enrich media on the lipid concentration and composition, biomass was collected at the beginning of the stationary phase and the lipid fraction was extracted. Results suggested that the two tested microalgae can growth in media enriched with WWW and the total Nitrogen concentrations decreased up to 90 and 100 % for A. platensis and C. vulgaris, respectively. In conclusion, WWW could be successfully used for the growth of the tested microalgae, leading to a reduction of the environmental impact of this wastewater

    The Effect of Tag Positioning on Passive Radio Frequency Identification (RFID) Performance: Case of Food Beverages

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    Smart packaging containing sensors could be considered the natural progression in packaging innovation for many consumer products. The goal of implementing sensors into the packaging is to improve product traceability and sustainability and to increase product shelf-life. Radio-frequency identification (RFID) systems have already been adopted for traceability purposes in many supply chains including apparel, electronics, pharmaceuticals, and food. The Ultra-High Frequency (UHF) range is widely used for those purposes. However, to improve the adoption of this technology several challenges need to be overcome. The goal of this research was to determine the best configuration for attaching a passive UHF RFID tag to different beverage bottles. To do this, three different packaging materials (polyethylene terephthalate (PET), clear glass, and Tetrapak®) which are commonly used in the beverage industries, and three commercially available passive UHF RFID tags with different designs were used. The influence of the RFID positioning (bottom or top) on the performance of tags using empty and water-filled bottles was assessed. Power on tag Forward and Theoretical Read Range were used as the indicators of the tag performance. The results of this study confirmed that tag positioning affects the performance of the RFID system. In order to have the best passive UHF RFID tag performance, packaging and labeling industries should consider the effect of tag design, packaging material, and food composition

    Influence of fructooligosaccharides on the fermentation profile and viable counts in a symbiotic low fat milk

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    Abstract This study evaluated the effects of prebiotics on fermentation profile and growth of Lactobacillus acidophilus, Lactobacillus bulgaricus, Lactobacillus rhamnosus, and Bifidobacterium lactis in co-cultures with Streptococcus thermophilus. Acidification rate and viability were positively influenced by the co-culture with B. lactis and by both inulin or oligofructose in low fat milk

    Fermentacija mlijeka obogaćenog mljevenom kominom grožđa s pomoću bakterije Lactobacillus acidophilus

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    Some by-products of wine industry still contain nutrients and functional compounds that make them potential ingredients to formulate new high value-added food products. The aim of this study is to develop milk fermented with Lactobacillus acidophilus fortified with marc flour of different cultivars of Vitis vinifera from wine production and to evaluate their influence on fermentation kinetics, probiotic counts, phenolic compounds, sugar content and antioxidant activity. The acidification time was significantly shortened by these enrichments (by up to 2.7 h), and the bacterial count during cold storage resulted in stronger fortification of samples (up to 4.13 %) when compared to control tests. Fermented milk containing grape marc showed considerable amounts of phenolic compounds with notable antioxidant activity, as well as significant amounts of total sugars. The most important aspect of this paper is the feasibility of using winery by-products, rich in phenolic compounds, as natural supplements to fortify probiotic-fermented milk.Neki nusproizvodi u proizvodnji vina sadržavaju hranjive i funkcionalne tvari, pa se mogu upotrijebiti za razvoj novih prehrambenih proizvoda s dodanom vrijednošću. Svrha je ovoga rada bila proizvesti mlijeko obogaćeno mljevenom kominom različitih sorata grožđa i fermentirano s pomoću bakterije Lactobacillus acidophilus, te odrediti utjecaj dodatka komine na kinetiku fermentacije, broj probiotičkih mikroorganizama, udjele fenolnih spojeva i šećera, te antioksidativnu aktivnost fermentiranog mlijeka. Vrijeme fermentacije obogaćenog mlijeka znatno se smanjilo (do 2,7 h), a broj bakterija tijekom skladištenja u hladnjaku povećao (do 4,13 %) u usporedbi s kontrolnim uzorkom. Fermentirano je mlijeko obogaćeno mljevenom kominom grožđa imalo veće udjele fenolnih spojeva i ukupnih šećera, te izraženiju antioksidativnu aktivnost. Najveći je značaj ovog istraživanja u tome što dokazuje da se nusproizvodi vinske industrije bogati fenolnim spojevima mogu upotrijebiti kao prirodni dodaci mlijeku fermentiranom s pomoću probiotika

    Innovative alternative technologies to extract carotenoids from microalgae and seaweeds

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    Marine microalgae and seaweeds (microalgae) represent a sustainable source of various bioactive natural carotenoids, including β-carotene, lutein, astaxanthin, zeaxanthin, violaxanthin and fucoxanthin. Recently, the large-scale production of carotenoids from algal sources has gained significant interest with respect to commercial and industrial applications for health, nutrition, and cosmetic applications. Although conventional processing technologies, based on solvent extraction, offer a simple approach to isolating carotenoids, they suffer several, inherent limitations, including low efficiency (extraction yield), selectivity (purity), high solvent consumption, and long treatment times, which have led to advancements in the search for innovative extraction technologies. This comprehensive review summarizes the recent trends in the extraction of carotenoids from microalgae and seaweeds through the assistance of different innovative techniques, such as pulsed electric fields, liquid pressurization, supercritical fluids, subcritical fluids, microwaves, ultrasounds, and high-pressure homogenization. In particular, the review critically analyzes technologies, characteristics, advantages, and shortcomings of the different innovative processes, highlighting the differences in terms of yield, selectivity, and economic and environmental sustainability

    Methylene blue adsorption using chabazite: Kinetics and equilibrium modelling

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    The adsorption of methylene blue from aqueous solution by a natural zeolite (chabazite) was studied. The effect of adsorbate concentration and pH were evaluated using raw and acid-treated chabazite. Fourier transform infrared spectroscopy analysis revealed surface modification of acid-treated chabazite, thus resulting in a decrease in adsorption capacity. The sorption kinetics and the equilibrium isotherms were evaluated. The pseudo-second-order model was found to be the most suited for kinetic results, and the Langmuir isotherm was chosen to better describe the sorption system. The results confirmed the efficacy of raw chabazite in removing almost all methylene blue fraction from the solution. The use of such a material, at low cost and easily available, can therefore represent a possible efficient way to remove dyes from effluent of many industries

    Ruptured Giant Hepatic Hemangioma: Report of A Case

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    "nHemangiomas are the most common benign liver masses with a frequency of 0.4-7.3% at autopsy. They are usually discovered incidentally and a few require surgery. Spontaneous or traumatic ruptures are among indications of surgery for hemangiomas. We report a case of giant hepatic hemangioma presenting as hemoperitoneum following use of the slimming belt that underwent an emergent laparotomy. Abdominal exploration revealed that both right and left lobes of the liver were involved with giant hemangiomas. The liver was compressed by tightly packing laparotomy pads. After the operation, the patient was admitted to the surgical intensive care unit. Two days later, a second surgery was performed to remove the laparotomy pads. On the 6th day, the patient was discharged. One month later, to shrink the tumor, percutaneous transarterial embolization of the hepatic artery was performed
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