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1.
Environ Sci Pollut Res Int ; 31(19): 27817-27828, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38517631

RESUMO

Water and several chemicals, including dyestuffs, surfactants, acids, and salts, are required during textile dyeing processes. Surfactants are harmful to the aquatic environment and induce several negative biological effects in exposed biota. In this context, the present study aimed to assess acute effects of five surfactants, comprising anionic and nonionic classes, and other auxiliary products used in fiber dyeing processes to aquatic organisms Vibrio fischeri (bacteria) and Daphnia similis (cladocerans). The toxicities of binary surfactant mixtures containing the anionic surfactant dodecylbenzene sulfonate + nonionic fatty alcohol ethoxylate and dodecylbenzene sulfonate + nonionic alkylene oxide were also evaluated. Nonionic surfactants were more toxic than anionic compounds for both organisms. Acute nonionic toxicity ranged from 1.3 mg/L (fatty alcohol ethoxylate surfactant) to 2.6 mg/L (ethoxylate surfactant) for V. fischeri and from 1.9 mg/L (alkylene oxide surfactant) to 12.5 mg/L (alkyl aryl ethoxylated and aromatic sulfonate surfactant) for D. similis, while the anionic dodecylbenzene sulfonate EC50s were determined as 66.2 mg/L and 19.7 mg/L, respectively. Both mixtures were very toxic for the exposed organisms: the EC50 average in the anionic + fatty alcohol ethoxylate mixture was of 1.0 mg/L ± 0.11 for V. fischeri and 4.09 mg/L ± 0.69 for D. similis. While the anionic + alkylene oxide mixture, EC50 of 3.34 mg/L for D. similis and 3.60 mg/L for V. fischeri. These toxicity data suggested that the concentration addition was the best model to explain the action that is more likely to occur for mixture for the dodecylbenzene sulfonate and alkylene oxide mixtures in both organisms. Our findings also suggest that textile wastewater surfactants may interact and produce different responses in aquatic organisms, such as synergism and antagonism. Ecotoxicological assays provide relevant information concerning hazardous pollutants, which may then be adequately treated and suitably managed to reduce toxic loads, associated to suitable management plans.


Assuntos
Aliivibrio fischeri , Benzenossulfonatos , Daphnia , Tensoativos , Águas Residuárias , Poluentes Químicos da Água , Tensoativos/toxicidade , Poluentes Químicos da Água/toxicidade , Águas Residuárias/química , Aliivibrio fischeri/efeitos dos fármacos , Animais , Daphnia/efeitos dos fármacos , Ecotoxicologia , Têxteis
2.
Environ Toxicol Chem ; 42(7): 1439-1450, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37057841

RESUMO

Certain emerging pollutants are among the most widely used chemicals globally, causing widespread concern in relation to their use in products devoted to cleaniness and asepsis. Nonylphenol ethoxylate (NPEOn) is one such contaminant, along with its degradation product, nonylphenol, an active ingredient presents in nonionic surfactants used as herbicides, cosmetics, paints, plastics, disinfectants, and detergents. These chemicals and their metabolites are commonly found in environmental matrices. Nonylphenol and NPEOn, used, are particularly concerning, given their role as endocrine disruptors chemical and possible neurotoxic effects recorded in several biological models, primarily aquatic organisms. Limiting and detecting these compounds remain of paramount importance. The objective of the present review was to evaluate the toxic effects of nonylphenol and NPEOn in different biological models. Environ Toxicol Chem 2023;42:1439-1450. © 2023 SETAC.


Assuntos
Disruptores Endócrinos , Poluentes Químicos da Água , Disruptores Endócrinos/toxicidade , Fenóis/análise , Modelos Biológicos , Poluentes Químicos da Água/toxicidade
3.
Environ Sci Pollut Res Int ; 30(12): 32168-32183, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36725801

RESUMO

Microemulsions are important for soil and sediment remediation technology. The characteristics of the surfactants that make up these microemulsions include low sorption into soil or sediments, low surface and interfacial tension, the ability to penetrate tiny pores, and good solubilization of contaminants. This review revealed that microemulsions formulated with nonionic and anionic surfactants have higher recovery efficiencies for hydrophobic contaminants than cationic ones, as evidenced by the surveyed studies reporting effective remediation of soils and sediments using on microemulsions. These microemulsified systems have been found to remove petroleum and its derivatives from soil or sediments at percentages ranging from 40 to 100%. As such, this review can aid with the choice of surfactants used in microemulsions for remediation, such as those with plant-based components, which are promising solutions for the remediation of contaminated soils due to their contaminant extraction efficiency and biodegradability.


Assuntos
Petróleo , Poluentes do Solo , Tensoativos/química , Solo , Poluentes do Solo/análise , Poluição Ambiental
4.
J Environ Sci Health B ; 57(12): 980-988, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36537054

RESUMO

Atrazine is an herbicide used worldwide, and it is considered a severe environmental contaminant. The present study aims to evaluate the atrazine adsorption in aqueous media in montmorillonite samples which were either in natural state or functionalized through saturation with lithium and pillarization with aluminum by different methods. Montmorillonite saturated with lithium adsorbed significantly more atrazine than the natural montmorillonite sample. Among the samples obtained through the three aluminum-pillarization methods, the mass percentage of adsorbed atrazine was very similar. However, the best combination was the aluminum-pillarization (due to the maintenance of the open interlayer region) and saturation with lithium (due to the significant reduction of the cation exchange capacity of the mineral), because both processes facilitate the interaction of atrazine with the montmorillonite. Another advantage was that the adsorption of atrazine in the pillared and lithium saturated samples had small desorption, which is desirable in the environmental perspective. It is recommended to build filters with aluminum-hydroxy pillared, lithium saturated montmorillonite as an alternative method to rapidly remove atrazine from aqueous media. In addition to the shorter production time, this process resulted in montmorillonite with high occupancy rate and stability of the aluminum-hydroxy pillars.


Assuntos
Atrazina , Bentonita , Adsorção , Alumínio , Lítio
5.
Environ Technol ; : 1-15, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36352347

RESUMO

ABSTRACTNonylphenol ethoxylate (NPE) is an endocrine-disrupting chemical that has bioaccumulative, persistent and toxic characteristics in different environmental matrices and is difficult to remove in sewage treatment plants. In this study, the effects of the initial concentration of NPE (0.2 ± 0.03 - 3.0 ± 0.02 mg. L-1) and ethanol (73.9 ± 5.0-218.6 ± 10.6 mg. L-1) were investigated using factorial design. Assays were carried out in anaerobic batch reactors, using the Zinder basal medium, yeast extract (200 mg. L-1), vitamin solution and sodium bicarbonate (10% v/v). The optimal conditions were 218.56 mg.L-1 of ethanol and 1596.51 µg.L-1 of NPE, with 92% and 88% of NPE and organic matter removal, respectively, and methane yield (1689.8 ± 59.6 mmol) after 450 h of operation. In this condition, bacteria potentially involved in the degradation of this surfactant were identified in greater relative abundance, such as Acetoanaerobium (1.68%), Smithella (1.52%), Aminivibrio (0.91%), Petrimonas (0.57%) and Enterobacter (0.47%), as well as archaea Methanobacterium and Methanoregula, mainly involved in hydrogenotrophic pathway.

6.
Environ Sci Pollut Res Int ; 29(21): 31384-31399, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35001267

RESUMO

Imazethapyr, a selective systemic herbicide, is widely used in agriculture and it is frequently detected in water bodies close to application areas. Like other agrochemicals, imazethapyr is commercialized in formulations containing a mixture of additives that increase the effectiveness of the active ingredient. These complex mixtures may cause adverse effects on non-target primary producers, such as microalgae, when they reach freshwater bodies. The aim of this study was to assess the effects, separately, of the formulation Verosil®, the formulation additives, and technical-grade imazethapyr, in the acidic form or as ammonium salt, on the microalga Scenedesmus vacuolatus (Chlorophyta). Verosil®, formulation additives, and acid imazethapyr significantly inhibited the growth of S. vacuolatus (Verosil® > formulation additives > acid imazethapyr) and caused morphological alterations from 2 mg L-1, 4 mg L-1, and 60 mg L-1 onwards, respectively. Verosil® and formulation additives caused the most adverse effect including membrane disorganization, cytoplasm contraction, cell wall thickening, thylakoidal membrane disaggregation, and starch granule accumulation. In addition, Verosil® and formulation additives increased the chl a/chl b ratio, indicating possible alterations in photosystems as a stress response. The carotene/chl a ratio was also increased in microalgae exposed to both Verosil® and formulation additives, suggesting an antioxidant response to these toxic compounds. All these results support the hypothesis that the formulation additives contribute significantly to the toxicity and alterations caused by the commercial formulation Verosil® on S. vacuolatus.


Assuntos
Herbicidas , Microalgas , Ácidos Nicotínicos , Scenedesmus , Poluentes Químicos da Água , Água Doce , Herbicidas/toxicidade , Ácidos Nicotínicos/farmacologia , Poluentes Químicos da Água/farmacologia
7.
Polymers (Basel) ; 13(21)2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34771182

RESUMO

Emulsion stabilization is a broad and relevant field with applications in oil, polymer and food industries. In recent years, the use of solid particles to stabilize emulsions or Pickering emulsions have been studied for their kinetic and physical properties. Nanomaterials derived from natural sources are an interesting alternative for this application. Cellulose nanofibrils (CNFs) have been widely explored as a Pickering emulsifier with potential food applications, however, in some cases the presence of surfactants is unavoidable, and the literature is devoid of an evaluation of the effect of a non-ionic food-grade surfactant, such as polysorbate 80, in the stabilization of a vegetable oil by CNFs. To better assess the possible interactions between CNFs and this surfactant emulsions containing coconut oil, an emerging and broadly used oil, were processed with and without polysorbate 80 and evaluated in their qualitative stability, morphological and physical properties. Fluorescence microscopy, dynamic light scattering and rheology were used for this assessment. Results indicate in absence of the surfactant, emulsion stability increased at higher CNFs content, creaming was observed at 0.15 and 0.3 wt.% of CNFs, while it was not evidenced when 0.7 wt.% was used. After the addition of surfactant, the droplets are covered by the surfactant, resulting in particles with a smaller diameter, entrapped in the cellulosic structure. Rheology indicates a lower network stiffness after adding polysorbate 80.

8.
Materials (Basel) ; 14(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200640

RESUMO

Surfactants are essential in the manufacture of polymeric nanoparticles by emulsion formation methods and to preserve the stability of carriers in liquid media. The deposition of non-ionic surfactants at the interface allows a considerable reduction of the globule of the emulsion with high biocompatibility and the possibility of oscillating the final sizes in a wide nanometric range. Therefore, this review presents an analysis of the three principal non-ionic surfactants utilized in the manufacture of polymeric nanoparticles; polysorbates, poly(vinyl alcohol), and poloxamers. We included a section on general properties and uses and a comprehensive compilation of formulations with each principal non-ionic surfactant. Then, we highlight a section on the interaction of non-ionic surfactants with biological barriers to emphasize that the function of surfactants is not limited to stabilizing the dispersion of nanoparticles and has a broad impact on pharmacokinetics. Finally, the last section corresponds to a recommendation in the experimental approach for choosing a surfactant applying the systematic methodology of Quality by Design.

9.
Int J Biol Macromol ; 187: 325-331, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34280448

RESUMO

Understanding nonionic surfactant-protein interactions is fundamental from both technological and scientific points of view. However, there is a complete absence of kinetic data for such interactions. We employed surface plasmon resonance (SPR) to determine the kinetic and thermodynamic parameters of bovine lactoferrin-Brij58 interactions at various temperatures under physiological conditions (pH 7.4). The adsorption process was accelerated with increasing temperature, while the desorption rate decreased, resulting in a more thermodynamically stable complex. The kinetic energetic parameters obtained for the formation of the activated complex, [bLF-Brij58]‡, indicated that the potential energy barrier for [bLF-Brij58]‡ formation arises primarily from the reduction in system entropy. [bLF-Brij58]○ formation was entropically driven, indicating that hydrophobic interactions play a fundamental role in bLF interactions with Brij58.


Assuntos
Cetomacrogol/metabolismo , Lactoferrina/metabolismo , Tensoativos/metabolismo , Temperatura , Adsorção , Cetomacrogol/química , Entropia , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Cinética , Lactoferrina/química , Ligação Proteica , Ressonância de Plasmônio de Superfície , Tensoativos/química
10.
Heliyon ; 7(4): e06926, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34007922

RESUMO

Oil spillage contamination has been one of the most common and challenging problems in marine ecosystems over the years due to frequent petroleum exploitation, washing, and transportation activities. The use of nature-derived surfactants has become an attractive approach to restore the sites affected by oil spillage. Several studies have demonstrated that nutrient addition is an efficient strategy to enhance oil biodegradation since microorganisms can use petroleum hydrocarbons as their carbon and energy source, thus favoring and increasing the hydrocarbons degradation rate. This study aimed to assess the effectiveness of a commercial bio-catalytic agent used in the biological remediation of crude oil-contaminated sites through the qualitative analysis of its properties. The tests applied to this bio-catalyst showed excellent results. For instance, the emulsification (E24) and critical micellar concentration (CMC) assays displayed average values of 74.47% and 40 mg L-1, respectively. A significant reduction of Chemical Oxygen Demand (COD), turbidity, and Total Petroleum Hydrocarbon Content (TPHC) were observed in all the samples with bio-catalytic agent solution and aeration system. The best water quality was achieved by the sample with the highest concentration (10000 ppm) of bio-catalytic agent solution. It displayed a Total Petroleum Hydrocarbon removal efficiency (RTPH) of 81.537% after 30 days of the remediation time.

11.
Int J Phytoremediation ; 21(7): 652-662, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30656954

RESUMO

This study evaluated remediation of the herbicide sulfentrazone in soils with three different mineralogies (kaolinite, hematite, and gibbsite) and three remediation sulfentrazone treatments (Canavalia ensiformis L., Crotalaria juncea L., and natural attenuation). This study was conducted in a factorial scheme, in triplicate with randomized block design. Sulfentrazone was applied at 0 and 400 g ha-1. We analyzed sulfentrazone residue in the soils by high-performance liquid chromatography and confirmed the results with bioassays of Pennisetum glaucum. Herbicide movement was greater in the kaolinitic soil without plant species. The retention of herbicide in the kaolinitic soil occurred in larger quantities in the 0-12 cm layer, with higher levels found in the treatments with plants. In the hematitic soil with C. juncea, all applied herbicides were concentrated in the 0-12 cm layer. In the other hematitic soil treatments, sulfentrazone was not detected by chemical analysis at any soil depth, although in many treatments, it was detected in the bioassay. Phytoremediation was more efficient with C. ensiformis grown in gibbsitic soil, reducing the sulfentrazone load by approximately 27%. Natural attenuation was more efficient than phytoremediation in oxidic soils due to soil pH and texture soils favored microbial degradation of the compound. Highlights The influence of soil mineralogy of herbicide sulfentrazone retention was evaluated. Canavalia ensiformis and Crotalaria juncea were evaluated as phytoremediation plants. Kaolinite soils presented great movement of sulfentrazone in the soil. Natural attenuation is more efficient in oxide soils than phytoremediation.


Assuntos
Poluentes do Solo , Solo/química , Biodegradação Ambiental , Sulfonamidas , Triazóis
12.
Colloids Surf B Biointerfaces ; 166: 152-160, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29571158

RESUMO

The effect of the nonionic detergents Brij-98 and Brij-58 over human erythrocytes was studied through quantitative hemolysis and in Langmuir films. Hemolytic tests revealed that Brijs are stronger membrane solubilizers than Triton X-100 (TX-100), with effective detergent/lipid ratios of 0.18 and 0.37 for Brij-98 and Brij-58, respectively. Experiments with Langmuir films provided significant information on the kinetics and thermodynamics of detergent-membrane interaction. The adsorption (ka) and desorption (kd) rate constants of Brijs were lower than those of TX-100. In the case of ka, that is probably due to their larger hydrophilic head (with twice (20) the oxyethylene units of TX-100). As for the thermodynamic binding constant, the linear and longer hydrophobic acyl chains of Brijs favor their stabilization in-between the lipids, through London van der Waals forces. Consequently, Kb,m values of Brij-98 (12,500 M-1) and Brij-58 (19,300 M-1) resulted higher than TX-100 (7500 M-1), in agreement with results from the hemolytic tests. Furthermore, Brij-58 binds with higher affinity than Brij-98 to bilayers and monolayers, despite its shorter (palmitic) hydrocarbon chain, showing that unsaturation restrains the detergent insertion into these environments. Our results provide significant information about the mechanism of interaction between Brijs and membranes, supporting their distinct solubilization effect.


Assuntos
Detergentes/química , Eritrócitos/metabolismo , Bicamadas Lipídicas/química , Cetomacrogol/química , Humanos , Cinética , Octoxinol/química , Solubilidade
13.
Arq. Inst. Biol. ; 85: e1022017, 2018. tab, graf
Artigo em Inglês | VETINDEX | ID: vti-19092

RESUMO

Bisphenol-A is currently considered an environmental pollutant, capable of interfering in the endocrine system of organisms and causing alterations in its development and reproductive system. An alternative method to the chemical treatment of this pollutant has been the use of oxidative enzymes, especially laccases produced by fungi. In order to reduce production costs, agro-industrial waste can be used in the culture medium composition. Nonionic surfactants, which are only slightly toxic to biological membranes, can be applied, as well as Tween 80, to facilitate the excretion of these enzymes into the culture medium. The objectives of this work were: a) characterize the immersion water of banana straw used in the formulation of the culture medium; b) evaluate laccase production by Pleurotus sajor-caju in culture medium with and without addition of Tween 80, through shaken flasks; c) evaluate the efficiency of the crude enzyme broth in degrading bisphenol-A. The shaken flasks were incubated at 30°C for 12 days. The immersion water had a C:N ratio of 13.8, ash percentage of 28.6%, and pH close to neutrality. The addition of Tween 80 on the culture medium (7.5%, m/v) yielded laccase activity and productivity values equal to 3,016.47 U L-1 and 502.7 U L-1 day-1, respectively. These values were 50 and 33.5 times higher than those obtained in the culture medium without addition of Tween 80 for laccase activity and productivity, respectively. The crude enzyme broth degraded 100% of bisphenol-A after 48 hours, regardless of concentration (500, 750 and 1,000 mg L-1).(AU)


O bisfenol-A é considerado um poluente ambiental capaz de interferir no sistema endócrino dos organismos, ocasionando alterações em seu desenvolvimento e sistema de reprodução. Um método alternativo ao tratamento químico desse tipo de poluente tem sido a utilização de enzimas oxidativas, especialmente as lacases, produzidas por fungos. A fim de diminuir custos de produção, resíduos agroindustriais podem compor o meio de cultivo. Assim, surfactantes não iônicos e pouco tóxicos para as membranas biológicas, como o Tween 80, podem ser utilizados para facilitar a excreção dessas enzimas para o meio de cultivo. Os objetivos deste trabalho foram: caracterizar quimicamente o resíduo água de imersão de palha de bananeira, usado na formulação do meio de cultivo; avaliar a produção de lacase por Pleurotus sajor-caju em meio de cultivo líquido (frascos Erlenmeyer) com e sem adição de Tween 80; e avaliar a eficiência do caldo enzimático bruto em degradar bisfenol-A. Os frascos foram incubados a 30°C, por 12 dias. A água de imersão apresentou relação C:N 13,8, percentual de cinzas 28,6% e pH próximo da neutralidade. O cultivo adicionado de Tween 80 (7,5%, m/v) propiciou valores de atividade e produtividade em lacase iguais a 3.016,47 U L-1 e 502,7 U L-1 dia-1, respectivamente. Esses valores são 50 e 33,5 vezes maiores que os obtidos no cultivo sem adição de Tween 80, para atividade e produtividade em lacase, respectivamente. O caldo enzimático bruto degradou 100% do bisfenol-A após 48 horas, independentemente da concentração (500, 750 e 1.000 mg L-1).(AU)


Assuntos
Polissorbatos , Tensoativos , Pleurotus , Sistema Endócrino , Musa , Lacase , Poluentes Ambientais , Enzimas
14.
Arq. Inst. Biol ; 85: e1022017, 2018. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-999077

RESUMO

Bisphenol-A is currently considered an environmental pollutant, capable of interfering in the endocrine system of organisms and causing alterations in its development and reproductive system. An alternative method to the chemical treatment of this pollutant has been the use of oxidative enzymes, especially laccases produced by fungi. In order to reduce production costs, agro-industrial waste can be used in the culture medium composition. Nonionic surfactants, which are only slightly toxic to biological membranes, can be applied, as well as Tween 80, to facilitate the excretion of these enzymes into the culture medium. The objectives of this work were: a) characterize the immersion water of banana straw used in the formulation of the culture medium; b) evaluate laccase production by Pleurotus sajor-caju in culture medium with and without addition of Tween 80, through shaken flasks; c) evaluate the efficiency of the crude enzyme broth in degrading bisphenol-A. The shaken flasks were incubated at 30°C for 12 days. The immersion water had a C:N ratio of 13.8, ash percentage of 28.6%, and pH close to neutrality. The addition of Tween 80 on the culture medium (7.5%, m/v) yielded laccase activity and productivity values equal to 3,016.47 U L-1 and 502.7 U L-1 day-1, respectively. These values were 50 and 33.5 times higher than those obtained in the culture medium without addition of Tween 80 for laccase activity and productivity, respectively. The crude enzyme broth degraded 100% of bisphenol-A after 48 hours, regardless of concentration (500, 750 and 1,000 mg L-1).(AU)


O bisfenol-A é considerado um poluente ambiental capaz de interferir no sistema endócrino dos organismos, ocasionando alterações em seu desenvolvimento e sistema de reprodução. Um método alternativo ao tratamento químico desse tipo de poluente tem sido a utilização de enzimas oxidativas, especialmente as lacases, produzidas por fungos. A fim de diminuir custos de produção, resíduos agroindustriais podem compor o meio de cultivo. Assim, surfactantes não iônicos e pouco tóxicos para as membranas biológicas, como o Tween 80, podem ser utilizados para facilitar a excreção dessas enzimas para o meio de cultivo. Os objetivos deste trabalho foram: caracterizar quimicamente o resíduo água de imersão de palha de bananeira, usado na formulação do meio de cultivo; avaliar a produção de lacase por Pleurotus sajor-caju em meio de cultivo líquido (frascos Erlenmeyer) com e sem adição de Tween 80; e avaliar a eficiência do caldo enzimático bruto em degradar bisfenol-A. Os frascos foram incubados a 30°C, por 12 dias. A água de imersão apresentou relação C:N 13,8, percentual de cinzas 28,6% e pH próximo da neutralidade. O cultivo adicionado de Tween 80 (7,5%, m/v) propiciou valores de atividade e produtividade em lacase iguais a 3.016,47 U L-1 e 502,7 U L-1 dia-1, respectivamente. Esses valores são 50 e 33,5 vezes maiores que os obtidos no cultivo sem adição de Tween 80, para atividade e produtividade em lacase, respectivamente. O caldo enzimático bruto degradou 100% do bisfenol-A após 48 horas, independentemente da concentração (500, 750 e 1.000 mg L-1).(AU)


Assuntos
Polissorbatos , Tensoativos , Pleurotus , Sistema Endócrino , Musa , Lacase , Poluentes Ambientais , Enzimas
15.
Adv Colloid Interface Sci ; 247: 178-184, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28780962

RESUMO

The Gibbs Adsorption Isotherm equation is a two-dimensional analogous of the Gibbs-Duhem equation, and it is one of the cornerstones of interface science. It is also widely used to estimate the surface excess concentration (SEC) for surfactants and other compounds in aqueous solution, from surface tension measurements. However, in recent publications some authors have cast doubt on this method. In the present work, we review some of the best available surface tension experimental data, and compare estimations of the SEC, using the Gibbs isotherm method (GIM), to direct measurements reported in the literature. This is done for both nonionic and ionic surfactants, with and without added salt. Our review leads to the conclusion that the GIM has a very solid agreement with experiments, and that it does estimate accurately the SEC for surfactant concentrations smaller than the critical micellar concentration (CMC).

16.
Membranes (Basel) ; 7(1)2017 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-28241433

RESUMO

The transformation of fog at a non-visible water layer on a membrane of low-density polyethylene (LDPE) and ethylene-vinyl acetate (EVA) was evaluated. Nonionic surfactants of major demand in the polyolefin industry were studied. A kinetic study using a hot fog chamber showed that condensation is controlled by both the diffusion and permanency of the surfactant more than by the change of the surface energy developed by the wetting agents. The greatest permanency of the anti-fog effect of the LDPE/EVA surface was close to 3000 h. The contact angle results demonstrated the ability of the wetting agent to spread out to the surface. Complementarily, the migration of nonionic surfactants from the inside of the polymeric matrix to the surface was analyzed by Fourier transform infrared (FTIR) microscopy. Additionally, electrical measurement on the anti-fogging membrane at alternating currents and at a sweep frequency was proposed to test the conductivity and wetting ability of nonionic surfactants. We proved that the amphiphilic molecules had the ability to increase the conductivity in the polyolefin membrane. A correlation between the bulk electrical conductivity and the permanency of the fogging control on the LDPE/EVA coextruded film was found.

17.
Braz. j. microbiol ; Braz. j. microbiol;47(3): 610-616, July-Sept. 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-788960

RESUMO

ABSTRACT This study aimed to investigate the impact of nonionic surfactants on the efficacy of fluorine degradation by Polyporus sp. S133 in a liquid culture. Fluorene was observed to be degraded in its entirety by Polyporus sp. S133 subsequent to a 23-day incubation period. The fastest cell growth rate was observed in the initial 7 days in the culture that was supplemented with Tween 80. The degradation process was primarily modulated by the activity of two ligninolytic enzymes, laccase and MnP. The highest laccase activity was stimulated by the addition of Tween 80 (2443 U/L) followed by mixed surfactant (1766 U/L) and Brij 35 (1655 U/L). UV-vis spectroscopy, TLC analysis and mass spectrum analysis of samples subsequent to the degradation process in the culture medium confirmed the biotransformation of fluorene. Two metabolites, 9-fluorenol (λmax 270, tR 8.0 min and m/z 254) and protocatechuic acid (λmax 260, tR 11.3 min and m/z 370), were identified in the treated medium.


Assuntos
Polyporus/metabolismo , Fluorenos/metabolismo , Solubilidade , Biodegradação Ambiental , Biotransformação , Biomassa , Poluentes Ambientais/metabolismo , Redes e Vias Metabólicas , Polyporus/enzimologia , Metaboloma , Metabolômica/métodos , Fluorenos/química
18.
Braz. J. Microbiol. ; 47(3): 610-616, Jul-Set. 2016. tab, graf
Artigo em Inglês | VETINDEX | ID: vti-23388

RESUMO

This study aimed to investigate the impact of nonionic surfactants on the efficacy of fluorine degradation by Polyporus sp. S133 in a liquid culture. Fluorene was observed to be degraded in its entirety by Polyporus sp. S133 subsequent to a 23-day incubation period. The fastest cell growth rate was observed in the initial 7 days in the culture that was supplemented with Tween 80. The degradation process was primarily modulated by the activity of two ligninolytic enzymes, laccase and MnP. The highest laccase activity was stimulated by the addition of Tween 80 (2443 U/L) followed by mixed surfactant (1766 U/L) and Brij 35 (1655 U/L). UV-vis spectroscopy, TLC analysis and mass spectrum analysis of samples subsequent to the degradation process in the culture medium confirmed the biotransformation of fluorene. Two metabolites, 9-fluorenol (max 270, tR 8.0 min and m/z 254) and protocatechuic acid (max 260, tR 11.3 min and m/z 370), were identified in the treated medium.(AU)


Assuntos
Polyporus/enzimologia , Polyporus/metabolismo , Fluorenos , Tensoativos/análise , Tensoativos/química , Biodegradação Ambiental
19.
Braz J Microbiol ; 47(3): 610-6, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27287336

RESUMO

This study aimed to investigate the impact of nonionic surfactants on the efficacy of fluorine degradation by Polyporus sp. S133 in a liquid culture. Fluorene was observed to be degraded in its entirety by Polyporus sp. S133 subsequent to a 23-day incubation period. The fastest cell growth rate was observed in the initial 7 days in the culture that was supplemented with Tween 80. The degradation process was primarily modulated by the activity of two ligninolytic enzymes, laccase and MnP. The highest laccase activity was stimulated by the addition of Tween 80 (2443U/L) followed by mixed surfactant (1766U/L) and Brij 35 (1655U/L). UV-vis spectroscopy, TLC analysis and mass spectrum analysis of samples subsequent to the degradation process in the culture medium confirmed the biotransformation of fluorene. Two metabolites, 9-fluorenol (λmax 270, tR 8.0min and m/z 254) and protocatechuic acid (λmax 260, tR 11.3min and m/z 370), were identified in the treated medium.


Assuntos
Fluorenos/metabolismo , Polyporus/metabolismo , Biodegradação Ambiental , Biomassa , Biotransformação , Poluentes Ambientais/metabolismo , Fluorenos/química , Redes e Vias Metabólicas , Metaboloma , Metabolômica/métodos , Polyporus/enzimologia , Solubilidade
20.
Rev. cuba. plantas med ; 20(3): 0-0, jul.-set. 2015. ilus, tab
Artigo em Espanhol | CUMED | ID: cum-61963

RESUMO

Introducción: la evaluación de plantas con efecto reductor en los lípidos plasmáticos, constituye una herramienta muy valiosa para el control de las dislipidemias. Objetivos: comprobar la efectividad farmacológica como hipolipemiante, de Talinum triangulare (Jacq.) Willd (Talinaceae) y Abelmoschus esculentus moench (Malvaceae), en dos biomodelos de ensayo. Métodos: se utilizó el fruto verde de A. esculentus y hojas frescas de Talinum triangulare. El material vegetal previo secado, se pulverizó para preparar extractos hidroalcohólicos, que una vez rotoevaporados, fueron suspendidos en agua para ser administrados a los modelos experimentales. El efecto hipolipémico de las plantas estudiadas se comprobó, en animales de experimentación, sometidos a dos modelos de inducción de hiperlipidemia; administración de solución de sacarosa al 63 por ciento durante 16 semanas y administración vía intraperitoneal del detergente no iónico Poloxamer 338, durante 48 horas a una dosis de 0,6 g/kg. Resultados: el extracto hidroalcohólico de A. esculentus (400 mg/kg) en el modelo de hiperlipemia por Dieta Rica en Sacarosa, mostró un efecto reductor de triacilglicéridos, superior al ácido nicotínico. En el modelo de hiperlipidemia por inducción con detergente no iónico, el extracto hidroalcohólico de Talinum triangulare (400 mg/kg), manifestó un efecto reductor de colesterol y triacilglicéridos, mayor que el ácido nicotínico y la atorvastatina. Conclusiones: los extracto hidroalcohólicos de A. esculentus y de Talinum triangulare expresaron efectos reductores de triacilglicérios por mecanismos de acción diferentes, superiores al ácido nicotínico en cada caso. El extracto hidroalcohólico de Talinum triangulare manifestó un potente efecto reductor de colesterol mayor que el ácido nicotínico y la atorvastatina(AU)


Introduction: assessment of plants with low plasmatic lipids effect is a power instrument to dislipidemias control. Objectives: to establish the pharmacological effectiveness as hipolipidemic agents of Talinum triangulare (Jacq.) Willd (Portulacaceae) and Abelmoschus esculentus Moench (Malvaceae) in two biomodel assays. Methods: in the present study we have researched the hypolipemic effect of Talinum triangulare (false spinach) and A. esculentus (okra) in experimental animals subjected to two models of hyperlipidemia induction; an intake of 63 percent sucrose solution for 16 weeks and an intake of Poloxamer 338 nonionic detergent via intraperitoneal for 48 hours at a dose of 0,6 g/kg. Results: the hydroalcoholic extract of A. esculentus, at a dose of 400 mg/kg showed triacilglicéridos reducing effect greater than nicotinic acid in the model of hyperlipidemia induction by a sucrose-rich diet. In the model of hyperlipidemia by induction with nonionic detergent, the hydroalcoholic extract of Talinum triangulare at a dose of 400 mg/kg, showed a powerful cholesterol and triacilglicéridos lowering effect, greater than nicotinic acid and atorvastatin. Conclusions: the hydroalcoholic extract of A. esculentus and T. triangulare showed hypotriglyceridemic effect for different action mechanisms, higher than the nicotinic acid, in each case. The extract hidroalcohólico of Talinum triangulare showed a potent hipocholesterolemic effect even more than the nicotinic acid and the atorvastatin(AU)


Assuntos
Animais , Abelmoschus , Dislipidemias/terapia , Preparações de Plantas/uso terapêutico
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