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1.
Environ Sci Pollut Res Int ; 28(1): 121-132, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33058075

RESUMO

Oily sludge contains high concentrations of total petroleum hydrocarbons and heavy metals, which seriously impact the environment and human health. How to dispose of and use the oily sludge has attracted an increasing amount of attention. This study introduces harmless and resource-based oily sludge treatment technologies. It summarizes the technologies from various aspects, such as the process principle, influencing factors, advantages, and disadvantages, and analyzes and summarizes the status quo of the development of the technologies. In comparison, the direction of processing technology development is discussed to provide reference for processing technology improvements, optimization, and efficiency improvements.


Assuntos
Metais Pesados , Petróleo , Humanos , Hidrocarbonetos , Óleos , Petróleo/análise , Esgotos
2.
Environ Pollut ; 269: 116118, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33280919

RESUMO

The robust and eco-friendly super-hydrophobic sponge with remarkable performances has been potential adsorption material for the treatment of offshore oil spills. In this work, the durable PDMS@SiO2@WS2 sponge was fabricated via a green and facile one-step dipping method. The mixed tungsten disulfide (WS2) microparticles and hydrophobic SiO2 nanoparticles were immobilized on the sponge by non-toxic polydimethylsiloxane (PDMS) glue tier, which featured the hierarchical structure and extreme water repellency with the water contact angle of 158.8 ± 1.4°. The obtained PDMS@SiO2@WS2 sponge exhibits high oil adsorption capacity with 12-112 times of its own weight, and oil/water selectivity with separation efficiency over 99.85%. Notably, when subjected to the complex marine environment including high temperature, corrosive condition, insolation, and strong wind and waves, the modified sponge can maintain sable super-hydrophobicity with water contact angle over 150°. Moreover, it possesses superior mechanical stability for sustainable reusability and oil recovery. The sponge fabricated by non-toxic modifiers along with its sable super-hydrophobicity in complex marine environment makes it a potential material for practical applications.


Assuntos
Óleos , Dióxido de Silício , Dimetilpolisiloxanos , Interações Hidrofóbicas e Hidrofílicas , Água
3.
Environ Sci Pollut Res Int ; 28(1): 16-34, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33009615

RESUMO

Water pollution is a global environmental problem that affects the ecosystem severely. Treatment of oily wastewater and organic pollutants is a major challenge that waits to be solved as soon as possible. Adsorbing is one of the most effective strategies to deal with this problem. Three-dimensional (3D) porous adsorbents made of graphene or graphene-based nanomaterials skeletons had attracted more attention in wastewater treatment because of their large surface area, high porosity, low density, high chemical/thermal stability, and steady mechanical properties, which allow different pollutants to easily access and diffuse into 3D networks of adsorbents. This work presents an extensive summarization of recent progress in the synthesis methodologies and microstructures of 3D graphene foams and 3D graphene-based foams and highlights their adsorption performance for oils and organic solvents. Advantages and disadvantages of various preparation strategies are compared and the corresponded structures of these skeletons are studied in detail. Furthermore, the effects of the structures on oil-adsorption properties are analyzed and some data and parameters of the oil-adsorption properties are listed and studied for easier comparison. At last, the future research directions and technical challenges are prospected, which is hoped that the researchers will be inspired to develop the new graphene-based adsorbents.


Assuntos
Grafite , Poluentes Químicos da Água , Adsorção , Ecossistema , Óleos , Esqueleto/química , Águas Residuárias , Poluentes Químicos da Água/análise
4.
Chemosphere ; 263: 128140, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297128

RESUMO

Direct-contact membrane distillation (DCMD) can be eminent solution for oily wastewater treatment if the membrane provided is slippery and tolerant to low surface tension complex solutions. This study describes preparation of an anti-oil-fouling omniphobic polyethersulfone membrane using fluorinated silica nanoparticles (F-SiO2@PES) combined with perfluorodecyl triethoxysilane and polydimethylsiloxane for application against oil-In-water (o/w) emulsions. Feed solutions consist of different concentrations of oil (hexadecane), different charge surfactants (anionic sodium dodecyl benzenesulfonate, non-ionic Tween 20, and cationic hexadecyltrimethylammonium bromide, and salt (NaCl). The hierarchical re-entrant micro structured surface of the omniphobic F-SiO2@PES membrane and functional groups are confirmed by atomic force microscopy, scanning electron microscopy, and Fourier-transform infrared spectroscopy. The anti-oil-fouling and anti-wetting performance of omniphobic F-SiO2@PES membranes are investigated using contact-angle, sliding angles, DCMD tests with multiple foulants of surfactants. Omniphobic F-SiO2@PES membrane exhibited effective anti-oil-fouling and anti-wetting performance against emulsions as no severe fouling and a conductivity rises were evident regardless of surfactant charge and the concentration of components. Flux reduction and rejection rates for the omniphobic F-SiO2@PES membranes are in a range of 5-15% (only) and >99%, respectively, for various combinations of feed solution components.


Assuntos
Destilação , Purificação da Água , Membranas Artificiais , Óleos , Dióxido de Silício
5.
J Environ Manage ; 278(Pt 2): 111572, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33157469

RESUMO

Suspended particulate matter (SPM) in marine environments plays an important role in determining the fate of spilled oil via the generation of oil-particle aggregates (OPAs). A series of mesoscale wave tank experiments and sedimentation tests were conducted to fill the knowledge gap on how the turbulent mixing, temperature, and oil type affect the dispersion of spilled oil and properties of OPAs. Generally, the oil dispersing efficiency was significantly enhanced by high wave energy, which also led to effective oil sinking, large size of OPAs and wide distribution of trapped oil. Nonlinear fitting results indicated that the oil sinking efficiency followed an exponential growth over time. The effect of temperature on oil dispersion and formation of OPAs is primarily attributed to its influence on oil viscosity and interfacial tension. Viscous oils are more likely to interact with particles above 25 °C. However, below 20 °C, a specific oil viscosity that will bring about the maximum OPAs exists. Excessive oil viscosity will lead to a weak binding between oil and SPM and a centralized distribution of trapped oil. Furthermore, spilled oil with a high asphaltene can interact more effectively with particles. Our finding suggested that early prevention of offshore oil sinking is key in summer.


Assuntos
Poluentes Químicos da Água , Óleos , Material Particulado , Temperatura , Viscosidade , Poluentes Químicos da Água/análise
6.
Food Chem ; 339: 127898, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32871303

RESUMO

In this study, lipid oxidation evaluation methods were compared for a krill-oil-in-water emulsion system. With this aim, thiocyanate and DPPP (diphenyl-1-pyrenylphosphine) fluorescence methods were comparatively examined to determine primary oxidation products. 2-thiobarbituric acid reactive substances (TBARS), hexanal and propanal formation were also monitored as secondary oxidations products. All oxidation experiments were performed via both auto-oxidation at 45 °C and light-riboflavin induced photooxidation at 37 °C. The results have shown that thiocyanate method was not suitable to measure lipid hydroperoxides by the both in auto- and photo-oxidation systems. On the other hand, fluorescence intensity of samples containing the DPPP probe increased during incubation period which indicates the formation of lipid hydroperoxides could be detected via this method. TBARS, hexanal and propanal concentrations also increased during storage period and the formation kinetics of secondary oxidation products was confirmed that the DPPP fluorescence method was accurate and reliable at different environmental conditions.


Assuntos
Emulsões/química , Euphausiacea/química , Óleos/química , Água/química , Animais , Antioxidantes/química , Euphausiacea/metabolismo , Compostos Organofosforados/química , Oxirredução , Tamanho da Partícula , Pirenos/química , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta
7.
J Food Sci ; 85(11): 3797-3805, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33067851

RESUMO

Antarctic krill oil (AKO) is usually encapsulated by the protein materials, enhancing its oxidative stability. Proteins exhibit immense effect on lipid oxidation and induce protein-lipid co-oxidation. This study aimed at elucidating the co-oxidation mechanism of AKO and whey protein (WP) or myofibrillar protein (MP) in oil-in-water emulsions. The estimations of malondialdehyde (MDA) content, phospholipid molecular species, and pyrrole content resulted in increased and decreased oxidation rate of AKO (especially phosphatidylethanolamine) by WP and MP, respectively. Meanwhile, protein concentration, sulfhydryl content, the loss of tryptophan fluorescence intensity, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis results demonstrated that AKO promoted WP oxidation but inhibited MP oxidation. Further, the antioxidative abilities of seven common antioxidants were evaluated. Ascorbyl palmitate showed the most substantial antioxidative effect for both AKO and proteins (about 70% decrease of MDA content and 30% decrease of the decrease ratio of tryptophan fluorescence intensity). This finding supported that different proteins could exhibit different pro/anti-oxidative effects on lipid oxidation, especially for marine lipids abundant in phospholipids and polyunsaturated fatty acids. Besides, MP could also act as antioxidant in MP AKO emulsions, further extending its application from traditional surfactants. PRACTICAL APPLICATION: AKO is usually encapsulated by the protein materials, enhancing its oxidative stability. The results demonstrated MP could inhibit AKO oxidation, and vice versa, especially when ascorbyl palmitate was added at the same time. As a result, this finding explored a new potential wall material with antioxidative ability for the encapsulated products of AKO.


Assuntos
Emulsões/química , Euphausiacea/química , Proteínas Musculares/química , Óleos/química , Proteínas do Soro do Leite/química , Animais , Antioxidantes/análise , Antioxidantes/química , Óleos/análise , Oxirredução
8.
Aquat Toxicol ; 228: 105651, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33049420

RESUMO

Many early stages of estuarine species congregate at the surface or in the upper mixing layer making them prone to UV light exposure and oil sheens. Laboratory testing was used to assess UV-oil sheen interactions with grass shrimp (Palaemon pugio). Newly hatched grass shrimp larvae were exposed to a 1-µm thick oil sheen for 24 h with or without an 8-h pulse of UV light. Grass shrimp were then transferred to clean seawater and non-UV conditions to measure development, growth, and reproductive fitness. Minimal toxicity was observed after the initial exposure but larval development was significantly delayed in shrimp exposed to the UV enhanced sheen. After reaching sexual maturity, shrimp were paired to evaluate effects on reproduction. Shrimp initially exposed to the UV enhanced sheen as larvae had a significant reduction in fecundity compared to controls. This demonstrates the importance of examining interactions between UV light and oil since negative effects to aquatic organisms may be underestimated if based on standard laboratory fluorescent lighting. Acute exposures of early life stages to thin oil sheens and UV light may lead to long-term impacts to individuals and ultimately to grass shrimp populations.


Assuntos
Exposição Ambiental , Óleos/toxicidade , Palaemonidae/crescimento & desenvolvimento , Palaemonidae/efeitos da radiação , Animais , Feminino , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/efeitos da radiação , Masculino , Palaemonidae/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/análise , Reprodução/efeitos dos fármacos , Reprodução/efeitos da radiação , Água do Mar , Raios Ultravioleta , Poluentes Químicos da Água/toxicidade
9.
Cochrane Database Syst Rev ; 10: CD003718, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33053612

RESUMO

BACKGROUND: Establishing the subgroup analysis of the fallopian tubes (tubes) is a commonly undertaken diagnostic investigation for women with subfertility. This is usually achieved by flushing contrast medium through the tubes and visualising patency on radiographs, ultrasonography or laparoscopy. Many women were noted to conceive in the first three to six months after tubal flushing, raising the possibility that tubal flushing could also be a treatment for infertility. There has been debate about which contrast medium should be used (water-soluble or oil-soluble media) as this may influence pregnancy rates. An important adverse event during tubal flushing is intravasation (backflow of contrast medium into the blood or lymphatic vessels),which could lead to embolism although it is asymptomatic in most cases. OBJECTIVES: To evaluate the effectiveness and safety of tubal flushing with oil-soluble contrast media (OSCM) and water-soluble contrast media (WSCM) on subsequent fertility outcomes in women with subfertility. SEARCH METHODS: We searched the Cochrane Gynaecology and Fertility Group Specialised Register of controlled trials, MEDLINE, Embase, CENTRAL, PsycINFO, reference lists of identified articles and trial registries. The most recent search was conducted in April 2020. SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing tubal flushing with OSCM, WSCM with each other or with no treatment, in women with subfertility. DATA COLLECTION AND ANALYSIS: Two review authors independently selected the trials, assessed risk of bias and extracted data. We contacted study authors for additional information. The overall quality of the evidence was assessed using GRADE methods. MAIN RESULTS: Fifteen trials involving 3864 women were included in this systematic review. Overall, the quality of evidence varied from very low to moderate: the main limitations were risk of bias, heterogeneity and imprecision. OSCM versus no treatment Four studies (506 women) were included in this comparison. Tubal flushing with OSCM may increase the odds of live birth (odds ratio (OR) 3.27, 95% confidence interval (CI) 1.57 to 6.85, 3 RCTs, 204 women, I2 = 0, low-quality evidence). This suggests that if the chance of live birth following no treatment is assumed to be 11%, the chance following tubal flushing with OSCM would be between 16% and 46%. Tubal flushing with OSCM may increase in the odds of clinical pregnancy (OR 3.54, 95% CI 2.08 to 6.02, 4 RCTs, 506 women, I2 = 18%, low-quality evidence). This suggests that if the chance of clinical pregnancy following no treatment is assumed to be 9%, the chance following tubal flushing with OSCM would be between 17% and 37%. No study measured intravasation or other adverse events such as infection, haemorrhage and congenital abnormalities. WSCM versus no treatment Only one study (334 women) was included in this comparison. We are uncertain whether tubal flushing with WSCM increase live birth compared to no treatment (OR 1.13, 95% CI 0.67 to 1.91, 1 RCT, 334 women, low-quality evidence). This suggests that if the chance of live birth following no treatment is assumed to be 21%, the chance following tubal flushing with WSCM would be between 15% and 33%. We are uncertain whether tubal flushing with WSCM increases clinical pregnancy compared to no treatment (OR 1.14, 95% CI 0.71 to 1.84, 1 RCT, 334 women, low-quality evidence). This suggests that if the chance of clinical pregnancy following no treatment is assumed to be 27%, the chance following tubal flushing with WSCM would be between 29% and 40%. One case with pelvic infection was reported in the WSCM group and no case with infection in the no treatment group in a one study (334 women). Meta-analysis was not performed due to the rare events. No study measured intravasation or other adverse events such as infection, haemorrhage and congenital abnormalities. OSCM versus WSCM Six studies (2598 women) were included in this comparison. Three studies reported live birth, including two with higher live birth in the OSCM group (OR 1.64, 95% CI 1.27 to 2.11, 1119 women; OR 3.45, 95% CI 1.97 to 6.03, 398 women); and one with insufficient evidence of a difference between groups (OR 0.92, 95% CI 0.60 to 1.40, 533 women). Given the substantial heterogeneity observed (I2 = 86%), meta-analysis was not performed. Tubal flushing with OSCM probably increased in the odds of intravasation (asymptomatic) compared to tubal flushing with WSCM (OR 5.00, 95% CI 2.25 to 11.12, 4 RCTs, 1912 women, I2 = 0, moderate-quality evidence). This suggests that if the chance of intravasation following tubal flushing with WSCM is assumed to be 1%, the chance following tubal flushing with OSCM would be between 2% and 9%. Tubal flushing with OSCM may increase the odds of clinical pregnancy (OR 1.42, 95% CI 1.10 to 1.85, 6 RCTs, 2598 women, I2 = 41%, low-quality evidence). This suggests that if the chance of clinical pregnancy following tubal flushing with WSCM is assumed to be 26%, the chance following tubal flushing with OSCM would be between 28% and 39%. We are uncertain whether tubal flushing with OSCM decreases the odds of infection (OR 0.22, 95% CI 0.04 to 1.22, 2 RCTs, 662 women, I2 = 0, very low-quality evidence) or haemorrhage (OR 0.65, 95% CI 0.40 to 1.06, 2 RCTs, 662 women, I2 = 0, very low-quality evidence). Three neonates with congenital abnormalities were reported in the OSCM group while no congenital abnormality was reported in the WSCM group in one study (1119 women). No meta-analysis was performed due to the rare events. AUTHORS' CONCLUSIONS: The evidence suggests that compared to no treatment, tubal flushing with OSCM may increase the chance of live birth and clinical pregnancy, while it is uncertain whether tubal flushing with WSCM improves those outcomes. Compared to tubal flushing with WSCM, OSCM may improve clinical pregnancy while meta-analysis was impossible for live birth due to heterogeneity. Evidence also suggests that OSCM is associated with an increased risk of asymptomatic intravasation. Overall, adverse events, especially long-term adverse events, are poorly reported across studies.


Assuntos
Meios de Contraste/uso terapêutico , Tubas Uterinas , Infertilidade Feminina/terapia , Irrigação Terapêutica/métodos , Viés , Meios de Contraste/química , Feminino , Humanos , Nascimento Vivo/epidemiologia , Óleos , Gravidez , Taxa de Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto , Solubilidade , Irrigação Terapêutica/efeitos adversos , Água
10.
J Food Sci ; 85(10): 3391-3399, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32920877

RESUMO

The purpose of this study was to determine the effect of high-intensity ultrasound (HIU) on the physical properties of an all-purpose shortening and to evaluate how these properties changed during storage (48 hr; 4, 12, and 24 weeks) at 5 °C and 25 °C. Samples were crystallized at 30 °C for 60 min with and without the application of HIU (20 kHz; 3.2 mm-diameter tip, 168 µm amplitude, 10 s). After crystallization, physical properties, such as hardness, elasticity, melting behavior, and solid fat content (SFC), were measured. These properties were also measured during storage. The effect of HIU was significant in changing the SFC, hardness, G' and G'', melting enthalpy, and microstructure of the samples. After 60 min of crystallization, the sonicated samples had higher values of SFC, hardness, elasticity, and melting enthalpy than the ones obtained without sonication (P < 0.05). Changes in these physical properties were associated with the microstructure of the samples since sonication generated smaller, more uniformly sized crystals as well as increased the number of crystals. No differences were observed in the G' of the sonicated samples stored at 25 °C as a function of storage period. The G' of the nonsonicated samples increased until 12 weeks of storage and was maintained up to 24 weeks, suggesting that sonication speed up the formation of a stable crystalline network. Samples stored at 5 °C showed higher value in hardness, G' and G'', and SFC than the ones stored at 25 °C. PRACTICAL APPLICATION: High-intensity ultrasound (HIU) has been widely used as an additional tool to change the crystallization behavior in various lipids; however, the long-term storage effect of HIU has not been studied before. This research evaluates the effect of HIU on the physical properties of a palm-based shortening stored up to 24 weeks at two different temperatures (25 and 5 °C). The application of HIU may help increase the stability of lipid during storage.


Assuntos
Gorduras/química , Óleos/química , Cristalização , Elasticidade , Manipulação de Alimentos , Dureza , Sonicação , Termodinâmica
11.
Chemosphere ; 254: 126873, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957285

RESUMO

The removal of organic pollutants from water is highly desired because of the development of industrial and social economy. Superhydrophilic and underwater superoleophobic membranes are emerging materials for effective oil/water separation. In this paper, superhydrophilic and underwater superoleophobic polypropylene (PP) melt-blown membranes were prepared through melt-blown and in situ growth method, achieving highly efficient oil/water separation. After in situ growth, polydopamine (PDA) grows on the surface of PP fibers, and the addition of coupling agent (3-aminopropyltriethoxysilane, APTES) can improve the stability of the membrane in harsh environments (1 M HCl, 1 M NaOH, 1 M NaCl). The PDA/APTES@PP membrane could dramatically enhance the wetting (water contact angle ∼0, underwater oil contact angle∼154°) compare with the pristine PP melt-blown membrane (water contact angle ∼130°, underwater oil contact angle ∼0). Moreover, the filtration performance is at a high level (∼99%). The behaviors are comparable or even superior to the typical reported results in the references (such as the mussel-inspired superhydrophilic PVDF membrane and copper mesh). This method provides a facile route to prepared multi-functional membrane for highly efficiency oil/water separation and industrial oily wastewater remediation.


Assuntos
Indóis/análise , Polímeros/análise , Cobre , Interações Hidrofóbicas e Hidrofílicas , Membranas Artificiais , Óleos , Águas Residuárias , Água , Purificação da Água , Molhabilidade
12.
J Am Heart Assoc ; 9(18): e017368, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32896206

RESUMO

E-cigarette or vaping product use-associated lung injury was recognized in the United States in the summer of 2019 and is typified by acute respiratory distress, shortness of breath, chest pain, cough, and fever, associated with vaping. It can mimic many of the manifestations of coronavirus disease 2019 (COVID-19). Some investigators have suggested that E-cigarette or vaping product use-associated lung injury was due to tetrahydrocannabinol or vitamin E acetate oil mixed with the electronic cigarette liquid. In experimental rodent studies initially designed to study the effect of electronic cigarette use on the cardiovascular system, we observed an E-cigarette or vaping product use-associated lung injury-like condition that occurred acutely after use of a nichrome heating element at high power, without the use of tetrahydrocannabinol, vitamin E, or nicotine. Lung lesions included thickening of the alveolar wall with foci of inflammation, red blood cell congestion, obliteration of alveolar spaces, and pneumonitis in some cases; bronchi showed accumulation of fibrin, inflammatory cells, and mucus plugs. Electronic cigarette users should be cautioned about the potential danger of operating electronic cigarette units at high settings; the possibility that certain heating elements may be deleterious; and that E-cigarette or vaping product use-associated lung injury may not be dependent upon tetrahydrocannabinol, vitamin E, or nicotine.


Assuntos
Dronabinol/toxicidade , Vapor do Cigarro Eletrônico/toxicidade , Sistemas Eletrônicos de Liberação de Nicotina , Lesão Pulmonar/induzido quimicamente , Pulmão/efeitos dos fármacos , Pneumonia/induzido quimicamente , Vaping/efeitos adversos , Vitamina E/toxicidade , Animais , Exposição por Inalação , Pulmão/patologia , Lesão Pulmonar/patologia , Modelos Animais , Óleos , Pneumonia/patologia , Ratos , Medição de Risco
13.
J Food Sci ; 85(10): 3244-3252, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32869332

RESUMO

Loading contents and chemical stability of lycopene were synergistically enhanced after dispersion in genipin-crosslinked-chitosan (CS) stabilized high internal phase emulsions (HIPEs). HIPEs could be prepared with the parameters for the emulsifiers of CS concentration from 0.5 to 5 mg/mL, pH value from 5.5 to 7.5, and CS/genipin mass ratio from 2:1 to 20:1. High loading content of lycopene, up to 0.25 wt% was achieved, with emulsifier in the final system only 1 mg/mL. As the loading contents were elevated, increasing amount of lycopene distributed in HIPEs in the form of insoluble crystals. Meanwhile, density of oil droplets decreased and the shape changed from polygon to sphere, which is supposed to be related to the interaction between the crystal and the oil-water interface. Stability of lycopene against ultraviolet, temperature, hydrogen peroxide, and iron ions was improved significantly, which could be ascribed to the layer of genipin-crosslinked-CS on oil droplet surface and the crystal status of lycopene. The storage stability of lycopene was improved tremendously after encapsulation by HIPEs. PRACTICAL APPLICATION: Low loading content of lycopene in emulsion systems is not conducive to the evaluation of its biological function in subsequent experiments, as well as their real application in food industry. It is also crucial to improve the stability of lycopene for the practical application in food industry. In this work, the loading content in delivery system and the chemical stability of lycopene are improved through encapsulation with high internal phase emulsions (HIPEs). The significance of these results may have implications in fields spanning from colloidal science to functional foods applications.


Assuntos
Licopeno/química , Óleos/química , Água/química , Emulsões/química , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Temperatura
14.
Mar Pollut Bull ; 159: 111483, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32892918

RESUMO

In this study, the formation and fate of oil-related aggregates (ORAs) from chemically dispersed oil in seawater (SW) were investigated at different temperatures (5 °C, 13 °C, 20 °C). Experiments in natural SW alone, and in SW amended with typical marine snow constituents (phytoplankton and mineral particles), showed that the presence of algae stimulated the formation of large ORAs, while high SW temperature resulted in faster aggregate formation. The ORAs formed at 5 °C and 13 °C required mineral particles for sinking, while the aggregates also sank in the absence of mineral particles at 20°. Early in the experimental periods, oil compound accumulation in ORAs was faster than biodegradation, particularly in aggregates with algae, followed by rapid biodegradation. High abundances of bacteria associated with hydrocarbon biodegradation were determined in the ORAs, together with algae-associated bacteria, while clustering analyses showed separation between bacterial communities in experiments with oil alone and oil with algae/mineral particles.


Assuntos
Poluição por Petróleo/análise , Petróleo , Poluentes Químicos da Água/análise , Biodegradação Ambiental , Hidrocarbonetos , Óleos , Água do Mar , Temperatura
15.
Water Sci Technol ; 81(12): 2650-2663, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32857750

RESUMO

The effects of different operating parameters on the treatment efficiency of oily wastewater in terms of biological oxygen demand (BOD) and chemical oxygen demand (COD) were measured. The analyses of BOD using OxiTop biosensors are reviewed regarding performance characteristics like linearity, response time, precision, agreement between BOD28 values obtained from the biosensors and the ultimate BOD (UBOD), as well as toxic resistance and COD. The wastewater samples were seeded with the bacteria, which were isolated in the current study from Kuwaiti oil-contaminated sand, such as Bacillus mycoidesis and Bacillus subtilis. After 18 days, the margin for saponin solution and oily wastewater using either Rhododcoccus (R), a mixture of Bacillus mycoidesis and Bacillus subtilis (M) or a mixture of R&M exhibited the maximum rate of BOD. It was found that the corresponding COD of the saponin solution (SS) ranged from 1,525 mg/l to 3,890 mg/l by distilled water and the mixture (RM), respectively. The COD of oily wastewater (WW) ranged from 2,900 mg/l to 4,450 mg/l by distilled water and the mixture of (RM), respectively. Moreover, the higher values of BOD28 were recorded when mixtures of bacteria were added together with the saponin solution or oily wastewaters. Furthermore, the average values of UBOD for the oily wastewater with RM or with amendment substance were increased by about 33.5% and 49.5%, respectively. However, BOD 28 /COD ratios for all the selected have been found to be less than 0.4, indicating low aerobic degradability.


Assuntos
Bacillus , Águas Residuárias , Análise da Demanda Biológica de Oxigênio , Hidrocarbonetos , Óleos , Eliminação de Resíduos Líquidos
16.
Bioresour Technol ; 318: 123913, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32753242

RESUMO

Solid waste residues from the extraction of essential oils are projected to increase and need to be treated appropriately. Valorization of waste via pyrolysis can generate value-added products, such as chemicals and energy. The characterization of lemon myrtle residues (LMR) highlights their suitability for pyrolysis, with high volatile matter and low ash content. Thermogravimetric analysis/derivative thermogravimetric revealed the maximum pyrolytic degradation of LMR at 335 °C. The pyrolysis of LMR for bio-oil production was conducted in a fixed-bed reactor within a temperature range of 350-550 °C. Gas chromatography-mass spectrometry showed that the bio-oil contained abundant amounts of acetic acid, phenol, 3-methyl-1,2-cyclopentanedione, 1,2-benzenediol, guaiacol, 2-furanmethanol, and methyl dodecanoate. An increase in pyrolysis temperature led to a decrease in organic acid and ketones from 18.09% to 8.95% and 11.99% to 8.75%, respectively. In contrast, guaiacols and anhydrosugars increased from 24.23% to 30.05% and from 3.57% to 7.98%, respectively.


Assuntos
Myrtus , Óleos Voláteis , Biocombustíveis/análise , Temperatura Alta , Óleos , Óleos Vegetais , Polifenóis , Pirólise , Resíduos Sólidos
17.
Environ Sci Pollut Res Int ; 27(34): 43138-43149, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32729034

RESUMO

The current demand for oil/water separation with an efficient, cost-effective, and environmentally friendly method is increasing. A laser-structured superhydrophobic/superoleophilic aluminum was prepared by using a nanosecond laser. The aluminum plate was used for oil/water separation without external force, which can replace the traditional porous materials. The effect of hole diameter and spacing on the effectiveness of oil/water separation is discussed. The results show that the aluminum plate with a hole size of 0.5 mm can be considered a more appropriate choice for the oil/water mixtures with large water content. In addition, complete separation of oil and water can be achieved in the hole spacing range of 1.0-3.0 mm. The oil separation speed can be increased without changing the water permeability by reducing the hole spacing, which is positively related to the hole spacing. Separation efficiencies were tested with various oil/water mixtures. The aluminum plate with a hole size of 0.5 mm can quickly separate the different oil mixtures with less than 50% oil content while achieving an oil separation efficiency of up to 99%. Due to the difference in dynamic viscosity of various oil phases, the separation efficiencies of the petrol, kerosene, and diesel are slightly different but can still be maintained above 99%. The laser-processed aluminum plate has several advantages of high porosity, high surface of superhydrophobic properties, and easy tunable structures. In practical applications, the hole size and the spacing should be appropriately adjusted according to specific conditions, such as different oils, the mixing ratios, etc., to obtain the best separation efficiency and speed.


Assuntos
Alumínio , Óleos , Interações Hidrofóbicas e Hidrofílicas , Porosidade , Água
18.
PLoS One ; 15(7): e0236837, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730369

RESUMO

Recent developments propose renewed use of surface-modified nanoparticles (NPs) for enhanced oil recovery (EOR) due to improved stability and reduced porous media retention. The enhanced surface properties render the nanoparticles more suitable compared to bare nanoparticles, for increasing the displacement efficiency of waterflooding. However, the EOR mechanisms using NPs are still not well established. This work investigates the effect of in-situ surface-modified silica nanoparticles (SiO2 NPs) on interfacial tension (IFT) and wettability behavior as a prevailing oil recovery mechanism. For this purpose, the nanoparticles have been synthesized via a one-step sol-gel method using surface-modification agents, including Triton X-100 (non-ionic surfactant) and polyethylene glycol (polymer), and characterized using various techniques. These results exhibit the well-defined spherical particles, particularly in the presence of Triton X-100 (TX-100), with particle diameter between 13 to 27 nm. To this end, SiO2 nanofluids were formed by dispersing nanoparticles (0.05 wt.%, 0.075 wt.%, 0.1 wt.%, and 0.2 wt.%) in 3 wt.% NaCl to study the impact of surface functionalization on the stability of the nanoparticle suspension. The optimal stability conditions were obtained at 0.1 wt.% SiO2 NPs at a basic pH of 10 and 9.5 for TX-100/ SiO2 and PEG/SiO nanofluids, respectively. Finally, the surface-treated SiO2 nanoparticles were found to change the wettability of treated (oil-wet) surface into water-wet by altering the contact angle from 130° to 78° (in case of TX-100/SiO2) measured against glass surface representing carbonate reservoir rock. IFT results also reveal that the surfactant treatment greatly reduced the oil-water IFT by 30%, compared to other applied NPs. These experimental results suggest that the use of surface-modified SiO2 nanoparticles could facilitate the displacement efficiency by reducing IFT and altering the wettability of carbonate reservoir towards water-wet, which is attributed to more homogeneity and better dispersion of surface-treated silica NPs compared to bare-silica NPs.


Assuntos
Nanopartículas/química , Óleos/isolamento & purificação , Dióxido de Silício/química , Tensoativos/química , Óleos/análise , Óleos/química , Tensão Superficial , Molhabilidade
19.
Environ Pollut ; 266(Pt 2): 115169, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32663729

RESUMO

The heating of edible oils during cooking activities promotes the emissions of pollutants that have adverse impacts on the health of humans. This study investigated the evaporative emissions of fifteen (15) commonly used cooking oils. Split-plot experimental design under the response surface methodology framework was used to study singular and interaction effects of influencing parameters (temperature, volume of cooking oil and time) on cooking oil evaporation rate and pollutants emissions (i.e. Particulate matter of aerodynamic diameter ≤1 µm (PM1.0); ≤2.5 µm (PM2.5); ≤10 µm (PM10); Total Suspended Particulate (TSP); Total Volatile Organic Compounds -TVOCs, and Carbon Monoxide- CO) on a groundnut oil sample that served as a case study. Obtained values of density, viscosity, kinematic viscosity, smoke, flash and fire points were; 873-917 kg/m3; 1.12-9.7 kg/ms; 2.4-3.4 m2/s; 96 -100 °C; 124-179 °C and 142-186 °C, respectively. The role of temperature as the most significant parameter influencing the rate of evaporative emissions was established. Evaporation rate and pollutants emission from unrefined samples were the highest. The restricted maximum likelihood (REML) analysis results suggested a strong relationship between the actual values and the predicted values as R-squared values obtained were greater than 0.8 for all the responses. These results suggest that minimal rates of evaporation and pollutants emission from heating cooking oils can be achieved with a high volume of the cooking oil at moderate temperature levels.


Assuntos
Poluentes Atmosféricos/análise , Poluentes Ambientais , Culinária , Monitoramento Ambiental , Humanos , Óleos , Material Particulado/análise
20.
Food Chem ; 333: 127448, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32663748

RESUMO

Antarctic krill oil (AKO) is an emerging dietary supplement containing metal ions that influence oil oxidation. Thus, this study focuses on the effect and mechanism of metal ions on phospholipid oxidation in AKO. Firstly, AKO containing Mg2+, Mn2+, Cu2+, Fe2+ and Fe3+ (200 µmol/kg) were prepared separately and incubated at 60 °C for 6 days. Peroxide value (POV) and malondialdehyde (MDA) content showed that Fe3+ exhibited the most effective prooxidative activity, with the prooxidative activity of Fe2(SO4)3 (water-soluble) being stronger than that of ferric oleate (FeOl, fat-soluble). In addition, phosphatidylethanolamine (PE) oxidation degree (more than 90%) was considerably greater than phosphatidylcholine (PC) oxidation degree (about 15%) in AKO. Differences in the structure of head group hindered chelation of PC with metal ions than PE due to electrostatic repulsion and steric hindrance. Therefore, PC significantly inhibited, while PE promoted, the oxidation of polyunsaturated triacylglycerol (TAG), like fish oil (p < 0.01).


Assuntos
Euphausiacea/química , Metais/química , Óleos/química , Fosfolipídeos/química , Animais , Regiões Antárticas , Cátions/química , Suplementos Nutricionais , Malondialdeído/química , Oxirredução , Fosfatidilcolinas/química , Fosfatidiletanolaminas/química , Triglicerídeos/química
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