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1.
J Environ Manage ; 269: 110741, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32560985

RESUMO

In this study, a mixture of waste plastics and papers were pyrolyzed under mild conditions in batch and tubular reactors. The decomposition reactions were enhanced by the use of synthetic zeolite-based catalysts to obtain a higher yield of volatiles and modifying the product composition. Especially the decomposition reactions and the product properties obtained from the different reactors were compared. Gases were analysed by GC-FID and GC-TCD. This fraction contains hydrogen, carbon-monoxide, carbon-dioxide and hydrocarbons. The pyrolysis oils have oxygen-containing compounds, such as alcohols, aldehyde, ketones, carboxylic acids or phenol and its derivative. Not only the reactor configurations but also the catalysts had an effect to the product properties, because the catalysts with alkali characters showed advanced behaviour in the reduction of oxygenated hydrocarbons, while high synthetic zeolite catalysts can increase the saturation and isomerization reactions. The long-term behaviour of the pyrolysis oils was followed by an accelerated aging test at 80 °C till 7 days. The catalysts can effectively reduce the rate of density and viscosity increase during the aging and the alkali catalysts showed beneficial properties in reducing the acidic components. In general, the aging properties were more favorable for pyrolysis oils obtained from the tubular reactor compared with the results in batch reactor.


Assuntos
Plásticos , Pirólise , Catálise , Temperatura Alta , Hidrocarbonetos , Óleos
2.
Sci Total Environ ; 729: 138956, 2020 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-32498169

RESUMO

To handle the impact of habitat transformations, the microbial cells developed mechanisms aimed at adjustment of their biological processes in response to signals indicating environmental changes. One of the first changes in their properties is observed on their surface, which has direct contact with the dynamically varying surroundings. In this study, we present results of changes in the cell surface properties which may have a decisive impact on the xenobiotics' bioavailability and microbial cell survival. These changes influence their ability to remove xenobiotics by accelerating and empowering this process. Moreover, the application of microorganisms exposed for long-term to hydrocarbons in bioremediation processes might have positive impact on biodegradation of the latter in the natural environment as well as natural microbial community diversity. This study demonstrates a variety of microbial cell mechanisms of adaptation to long-term exposure to hydrocarbons and their potential as the bioremediation tools.


Assuntos
Bactérias , Biodegradação Ambiental , Água Doce , Hidrocarbonetos , Microbiota , RNA Ribossômico 16S
3.
Sci Total Environ ; 734: 139452, 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32464383

RESUMO

Owing to the less volatile and less biodegradable nature of weathered fuel-contaminated soil, it cannot be easily remediated using conventional bioremediation approaches. Therefore, this study was aimed to enhance the landfarming bioremediation process by introducing post-oxidation for the degradation of the residual total petroleum hydrocarbons (TPH) in fuel-contaminated field soil. A laboratory-scale landfarming bioaugmentation process was performed by using oil-degrading microbes, nutrients, and surfactants, followed by chemical oxidation as a post treatment. The results demonstrated that the addition of microbes and nutrients gradually decreased the TPH concentration of the soil (initial TPH = 5932 ± 267 mg/kg) with a removal efficiency of 70-72% (TPH > 800 mg/kg; Korean limit for non-residential sites). However, the use of post-oxidation treatments with 5% KMnO4 decreased the TPH to approximately 401-453 mg/kg (TPH below 500 mg/kg; residential site limit) with an overall efficiency of 92-93% compared to the corresponding value of 13% for the control (water treatment). Performing landfarming through biodegradation followed by chemical oxidation as a post treatment could successfully remove the weathered TPH in soil below the regulatory limits. Furthermore, the post-oxidation treatment may oxidize the less biodegradable portions only after biodegradation, thereby minimizing the oxidant demand and enhancing the soil properties such as the pH, amount of natural substrates and microbial population.


Assuntos
Solo , Biodegradação Ambiental , Hidrocarbonetos , Petróleo , Microbiologia do Solo , Poluentes do Solo
4.
Waste Manag ; 110: 1-9, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32445912

RESUMO

Bitumen ages in the short and long-term due to environmental conditions. As the bitumen ages, it loses its original properties and flexibility. Hardened bitumen causes certain distresses in pavement that may endanger traffic safety and reduce travel comfort. Bitumen is one of recoverable material, however some techniques may not be ecological due to considerable energy, time, and cost. On the other hand, recovering of aged bitumen might be eco-friendlier, energy-efficient, and economic by using bio-based waste materials such as waste vegetable cooking oils (WVCO). In this perspective, this paper was established on the idea of sustainable recovery of aged bitumen and WVCO. Base bitumen was aged in case of short-term (ST) and long-term (LT) in laboratory condition and modified with WVCO ranging from 2 to 10% by weight of bitumen. To determine the effect of WVCO modification on aged bitumen conventional and rheological test methods were utilized. To find the optimum rate of WVCO for full recovery of aged bitumen, an index called Pure Rejuvenation Index (PRI) was specified and applied for each test results. It can be concluded from PRI analyses that WVCO can be used as rejuvenator to recover aged bitumen and approximately 3% and 6% of WVCO are required for ST and LT aged bitumen cases, respectively. However, different test methods yield different optimum rates of WVCO for ST and LT aged bitumen. Recovering of WVCO and aged bitumen by using together may provide environmental protection and conservation of resources.


Assuntos
Hidrocarbonetos , Verduras , Culinária
5.
Sci Total Environ ; 732: 139293, 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32438147

RESUMO

Biodegradation is a major determinant of chemical persistence in the environment and an important consideration for PBT and environmental risk assessments. It is influenced by several environmental factors including temperature and microbial community structure. According to REACH guidance, a temperature correction based on the Arrhenius equation is recommended for chemical persistence data not performed at the recommended EU mean surface water temperature. Such corrections, however, can lead to overly conservative P/vP assessments. In this paper, the relevance of this temperature correction is assessed for petroleum hydrocarbons, using measured surface water (marine and freshwater) degradation half-time (DT50) and degradation half-life (HL) data compiled from relevant literature. Stringent screening criteria were used to specifically select data from biodegradation tests containing indigenous microbes and conducted at temperatures close to their ambient sampling temperature. As a result, ten independent studies were identified, with 993 data points covering 326 hydrocarbon constituents. These data were derived from tests conducted with natural seawater, or freshwater, at temperatures ranging from 5 to 21 °C. Regressions were performed on the full hydrocarbon dataset and on several individual hydrocarbons. The results were compared to the trend as predicted by the Arrhenius equation and using the activation energy (Ea) as recommend in the REACH Guidance. The comparison shows that the correction recommended in REACH Guidance over predicts the effect of temperature on hydrocarbon biodegradation. These results contrast with temperature manipulated inocula where the test temperature is different from the ambient sampling temperature. In these manipulated systems, the effect of temperature follows the Arrhenius equation more closely. In addition, a more striking effect of temperature on the lag phase was observed with longer lag phases more apparent at lower temperatures. This indicates that the effect of temperature may indeed be even lower when considering hydrocarbon biodegradation without the initial lag phase.


Assuntos
Biodegradação Ambiental , Água Doce , Hidrocarbonetos , Petróleo , Água do Mar
6.
Water Sci Technol ; 81(3): 445-455, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32385198

RESUMO

This study was aimed to investigate the removal processes of nitrogen (TN), NH4+-N and phosphorus (TP) from surface runoff by performing experiments on the filter layers in porous asphalt pavement (PAP). Experiments were conducted to compare the differences of the filter layer placed at the top, the middle or the bottom of PAP. The effects of retention time on the removal of the pollutants and the adsorption capacity of PAP materials were also investigated. Results indicated that the filter layer placed under the bed course improved the removal rates of pollutants compared to the other two cases on the whole. The concentration of TP in the effluent decreased by 80% after the 48 h retention time. In conclusion, this study demonstrated that the positions of filter layers and the temporary retention time of surface runoff within the bed course of PAP were critical parameters for determining the removal processes of pollutants. Thus, a certain retention time for surface runoff in bed course is of great importance for PAP to serve as an effective low impact development technology for stormwater management.


Assuntos
Fósforo , Poluentes Químicos da Água , Hidrocarbonetos , Nitrogênio , Porosidade , Chuva
7.
Sci Total Environ ; 730: 139117, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32402972

RESUMO

Soil pollution caused by petroleum hydrocarbons is a widespread environmental problem. Composting is one of the cost-effective solutions for petroleum hydrocarbons removal but limited by low efficiency of bioremediation, leading to high phytotoxicity. Given that biogas slurry as nutrients can alter the microbial activity, the aim of this study was to investigate the role of biogas slurry on the remediation of petroleum contaminated soils in composting. Herein, we added biogas slurry into the composting of hydrocarbon contaminated soil to investigate its effect on the biodegradation of petroleum hydrocarbons, humic acid (HA) transformation and the safety of product. The results showed that biogas slurry addition improved the degradation of organic matter and total petroleum hydrocarbons (TPH) (especially C > 16), but also increased 18.0% of germination index and the humification degree of HA. The estrone from biogas slurry was removed during composting and did not affect the phytotoxicity level of compost. Redundancy analysis and structural equation modeling indicated that TPH degradation was significantly related to the humification of HA components and total nitrogen from biogas slurry, which contributed to composting safety. Therefore, biogas slurry could be a possible activator for the remediation of petroleum contaminated soils through composting mediated by HA transformation, which is beneficial to obtain the composts with a lower phytotoxicity and higher maturity for soil application.


Assuntos
Compostagem , Biodegradação Ambiental , Biocombustíveis , Hidrocarbonetos , Petróleo , Solo , Microbiologia do Solo , Poluentes do Solo
8.
Sci Total Environ ; 729: 139010, 2020 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-32361457

RESUMO

Ambient hydrocarbons are important precursors of ground-level ozone and secondary organic aerosol formation. However, few studies have assessed the health impact of airborne hydrocarbons. We conducted this time series ecological study to evaluate the association of short-term airborne hydrocarbons exposure with hospital admissions for respiratory diseases, while controlling for co-exposure to criteria pollutants. Taipei air pollution and weather data for the period spanning from January 2010 to December 2017 were obtained from Taiwan Air Quality Monitoring Network. Subsequently, daily pollutant concentrations were linked with daily hospital admission counts for respiratory diseases into a time series data frame. The standard generalized additive Poisson model adjusted for temporal trends, seasonal variations, weather conditions, and calendar effects, was applied to examine the short-term associations of acute airborne hydrocarbon exposure with respiratory hospital admissions. Next, the robustness of the associations was tested using two-pollutant models with further adjustment for fine particulate matter (PM2.5) and gaseous pollutants. The results demonstrated that an interquartile range increase in non-methane hydrocarbon (NMHC) exposure on lag0 day (0.15 ppm) was associated with a 0.86% (95% confidence interval: 0.37%-1.36%), 2.06% (0.77%-3.38%), and 1.25% (0.31%-2.20%) increment in all-respiratory-disease-, asthma-, and chronic-obstructive-pulmonary-disease-linked hospital admissions, respectively. The associations were robust with further adjustment for co-exposure to PM2.5 and ozone. The acute effect estimate of methane on each respiratory category was sensitive to the co-pollutant adjustment and lost statistical significance in the two-pollutant models. In conclusion, we confirmed that airborne NMHC exposure increased the risk of respiratory-disease-related hospital admissions in Taipei; this information may aid in the regulation of hydrocarbon pollution.


Assuntos
Poluição do Ar , Poluentes Atmosféricos , Hospitalização , Hidrocarbonetos , Metano , Material Particulado , Taiwan
9.
J Environ Manage ; 267: 110647, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32421677

RESUMO

Commercial kitchen wastewaters are typically strong organic and fat-rich effluents, often identified as major contributors to fatberg formation and associated blockages in sewers. Experimental trials were done using synthetic kitchen wastewater to understand the complex reactions involved in microbial remediation in grease traps/separators prior discharge in sewers. The principle organic components (FOG, carbohydrate and protein nitrogen), were varied using ranges observed in a previous study on real kitchen wastewater characterisation. A model bacterium, Bacillus licheniformis NCIMB 9375, was used to evaluate microbial utilisation of the different organic fractions in relation to fat, oil and grease (FOG) degradation. Novel results in the treatment of these effluents showed that, the presence and concentration of alternative carbon sources and the ratio of carbon to nitrogen (COD:N) had great influence on FOG-degradation response. For example, FOG removal decreased from 24 to 10 mg/l/h when glucose was substitute for starch at equivalent concentrations (500 mg/l); and from 26 to 5 mg/l/h when initial COD:N increased from 45:1 to 147:1. The dominant influence of COD:N was validated using a commercial bioadditive and real kitchen wastewater adjusted to different COD:N ratios, confirming the strong influence of kitchen wastewater composition on bioremediation outcomes. These results can therefore have major implications for biological management of FOG in kitchens and sewers as they provide a scientific explanation for bioremediation success or failure.


Assuntos
Óleos , Águas Residuárias , Biodegradação Ambiental , Hidrocarbonetos
10.
Bioresour Technol ; 310: 123473, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32389430

RESUMO

The global economy is threatened by the depletion of fossil resources and fluctuations in fossil fuel prices, and thus it is necessary to exploit sustainable energy sources. Carbon-neutral fuels including bio-oil obtained from biomass pyrolysis can act as alternatives to fossil fuels. Co-pyrolysis of lignocellulosic biomass and plastic is efficient to upgrade the quality of bio-oil because plastic facilitates deoxygenation. However, catalysts are required to produce bio-oil that is suitable for potential use as transportation fuel. This review presents an overview of recent advances in catalytic co-pyrolysis of biomass and plastic from the perspective of chemistry, catalyst, and feedstock pretreatment. Additionally, this review introduces not only recent research results of acid catalysts for catalytic co-pyrolysis, but also recent approaches that utilize base catalysts. Future research directions are suggested for commercially feasible co-pyrolysis process.


Assuntos
Petróleo , Plásticos , Biocombustíveis , Biomassa , Catálise , Temperatura Alta , Hidrocarbonetos , Pirólise
11.
Chemosphere ; 253: 126678, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32278192

RESUMO

Hypoxia and petrogenic hydrocarbon contamination are two anthropogenic stressors that coexist in coastal environments. Although studies have estimated the impact of each stressor separately, few investigations have assessed the effects of these stressors in interaction. We therefore investigated the impact of these combined stressors on sea bass, (Dicentrarchus labrax) physiology. After experimental contamination with physically dispersed oil, fish were exposed to hypoxia or normoxia, and active/standard metabolic rates (AMR and SMR, respectively), and metabolic scope (MS) were estimated. At the protocol's end, the uptake of polycyclic aromatic hydrocarbons (PAHs) was estimated by evaluating relative concentrations of bile metabolites. In terms of bile metabolites, our results validated the uptake of PAHs by contaminated fish in our experimental settings, and further suggest that the hypoxic period after contamination does not reduce or increase compound metabolization processes. Our data showed significant effects of hypoxia on all metabolic rates: a significant drastic AMR reduction and significant SMR diminution led to decreased MS. We also found that oil contamination significantly impacted AMR and MS, but not SMR. These results suggested that when evaluated separately, hypoxia or oil affect the metabolic rate of sea bass. On the other hand, when evaluated in combination, no cumulative effects were observed, since fish exposed to both stressors did not show a stronger impact on metabolism than fish exposed to hypoxia alone. This suggests that oil impacts fish metabolism when fish occupy normoxic waters, and that oil does not magnify hypoxia-induced effects on fish metabolism.


Assuntos
Bass/fisiologia , Poluição por Petróleo , Aerobiose/efeitos dos fármacos , Animais , Bass/metabolismo , Bile/metabolismo , Hidrocarbonetos/metabolismo , Hipóxia/metabolismo , Hipóxia/veterinária , Hidrocarbonetos Policíclicos Aromáticos/metabolismo
12.
Chemosphere ; 253: 126617, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32278905

RESUMO

Remediation of wetland soils contaminated with petroleum hydrocarbons is a challenging task. Biosurfactant and biochar have been used in oil remediation. However, little is known about the ecotoxicity of these materials when applied in wetland ecosystems. In this study, the ecotoxicity of biochar and rhamnolipid (RL) biosurfactant as crude oil remediation strategies in a Louisiana wetland soil was investigated. A pot experiment was set up with wetland soil treated with/without crude oil followed by subjecting to application of 1% biochar and various levels of RL ranging from 0.1% to 1.4%. The ecotoxicity was evaluated regarding to high plant (S. Alterniflora), algae, and soil microbes. Specifically, after a 30-day growth in a controlled chamber, plant biomass change as well as shoot/root ratio was measured. Algae growth was estimated by quantifying chlorophyll by spectrometry following separation, and soil microbial community was characterized by phospholipid fatty acids analysis. Results showed that plant can tolerate RL level up to 0.8%, while algae growth was strongly inhibited at RL > 0.1%. Algal biomass was significantly increased by biochar, which offset the negative impact of oil and RL. Additionally, soil microbial community shift caused by crude oil and RL was alleviated by biochar with promoting Gram-positive bacteria, actinomycetes, and arbuscular mycorrhizal fungi. Overall, this study shows that integrated treatment of biochar and RL has the lowest ecotoxicity to plant and algae when used in oil remediation of contaminated wetland soils.


Assuntos
Carvão Vegetal/química , Recuperação e Remediação Ambiental/métodos , Glicolipídeos/química , Petróleo/toxicidade , Poluentes do Solo/toxicidade , Áreas Alagadas , Biodegradação Ambiental , Biomassa , Ecossistema , Hidrocarbonetos , Louisiana , Micorrizas , Petróleo/análise , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise , Poluentes do Solo/química
13.
Mar Pollut Bull ; 153: 111001, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32275550

RESUMO

The Arctic is an ecologically diverse area that is increasingly vulnerable to damages from oil spills associated with commercial vessels traversing newly open shipping lanes. The significance of such accidents on Arctic marine habitats and the potential for recovery can be examined using ecological risk assessment (ERA) coupled with a dynamic object-oriented Bayesian network (DOOBN). A DOOBN approach is useful to represent the probabilistic relationships inherent in the interactions between key events associated with an oil spill, including oil dispersion from the source, ice-oil slick interactions, seawater-oil slick formation, sedimentation, and exposures to different aquatic life. From such analysis, a probabilistic cost analysis can be performed to examine the theoretical cost of habitat services lost and restored. The application of an ERA-DOOBN model to assess oil spills in the Arctic is demonstrated using a case study. The utility of the model output for determining habitat restoration costs and developing policy guidelines for ecological response measures in the Arctic is also discussed.


Assuntos
Poluição por Petróleo/estatística & dados numéricos , Regiões Árticas , Teorema de Bayes , Hidrocarbonetos , Medição de Risco/métodos , Água do Mar
14.
Mar Pollut Bull ; 153: 111003, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32275551

RESUMO

Diluted bitumens are produced by adding lower viscosity diluent to highly viscous bitumen to enable it to flow through pipelines and thus may behave differently than conventional oils when spilled into coastal seawater. Simulated surface spills using three different diluted bitumen products were carried out in May, July and November and water column hydrocarbons were monitored over a 14 day period. Volatile and total petroleum hydrocarbons varied in the water column depending on season and type of diluent. In summer, products diluted with synthetic crude or a mixture of condensate and crude released droplets into the water column. Diluted bitumen did not sink to the bottom of the enclosures with surface slicks showing a range of weathering after 14 d. With most of the diluted bitumen product remaining on the surface for 14 d, a rapid conventional clean up response may be effective in low energy, coastal waters.


Assuntos
Hidrocarbonetos/análise , Poluição por Petróleo , Petróleo , Poluentes Químicos da Água , Monitoramento Ambiental
15.
Mar Pollut Bull ; 153: 111034, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32275574

RESUMO

A small No. 2 fuel oil spill contaminated a Mytilus edulis population in the Cape Cod Canal, Massachusetts, USA during a three day period in April 1983. Retention and release of the fuel oil compounds were assessed over several days and months. Compounds analyzed included n-alkanes, pristane, phytane, C2 -, C3 -naphthalenes, flourene, phenanthrene, C1-, C2-, C3 - phenanthrenes. Biological half-lives were calculated for the release of the compounds up to day 29 and ranged from 1.5 days to 9.9 days. Results compared favorably with similar data from a small No. 2 fuel oil spill contaminating the same population of Mytilus edulis at the same time of year, April 1978. Gas chromatography-mass spectrometer analyses of C2-, and C3- phenanthrenes documented changes in relative abundance within the isomer groupings after day 29. This suggests a within isomer grouping molecular structural control on release or enzymatic catalyzed alteration of these compounds.


Assuntos
Mytilus edulis , Poluição por Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Animais , Baías , Monitoramento Ambiental , Óleos Combustíveis , Hidrocarbonetos , Massachusetts
16.
Chemosphere ; 253: 126648, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32298911

RESUMO

Catalyzed H2O2 propagations (CHP) have demonstrated great potential in the remediation of chlorinated aliphatic hydrocarbons (CAHs) like trichloroethene (TCE) contaminated groundwater. However, the importation of highly unstable H2O2 into subsurface environment remains challenging. In this work, the in-situ H2O2 generation reaction between glucose oxidase (GOD) and glucose was applied in combination with Fe(II) to form the modified Fenton system (GMFs) and its performance in TCE oxidative degradation was investigated. The influence of reactant concentration as well as environmental factors like temperature and pH on the kinetics of TCE oxidation in GMFs were studied. At optimized conditions, about 78% TCE were removed within 8 h in GMFs, which remained effective over the temperature range of 15-30 °C and pH range of 3.6-6.0 (in acetate buffer). The in-situ H2O2 and OH generation capacity of GMFs were further investigated to elucidate their functional mechanism on TCE oxidation. Intermediate and product analysis indicated the near-complete release of chloride ion by TCE oxidation with few organic chlorinated intermediates detected. This work reveals the potential of GMFs for CAHs contaminated groundwater remediation through in-situ generation of reactive oxygen species.


Assuntos
Recuperação e Remediação Ambiental/métodos , Glucose Oxidase/química , Espécies Reativas de Oxigênio/química , Poluentes Químicos da Água/química , Catálise , Cloro , Água Subterrânea/química , Hidrocarbonetos , Peróxido de Hidrogênio , Oxirredução , Tricloroetileno/metabolismo , Poluentes Químicos da Água/metabolismo
17.
Environ Monit Assess ; 192(5): 287, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32296943

RESUMO

The purpose of this study was to elucidate the capacity of a Pseudomonas aeruginosa strain to metabolize hydrocarbons sludge in the production of biosurfactants to fight against environmental threats. The performance of the treatment consisted in monitoring the inductive metabolism of the strain during 48 h at a temperature of 37 °C which constitutes an opportunity of treatment of various hydrocarbons contained in crude oil and spilled in the ecosystem to prevent pollution and damage. The results showed that a treatment rate of 96,8% and an emulsification index of 71.8% were obtained corresponding to a phosphate buffer concentration of 30 mmol/L. The main role of the biosurfactants produced was to emulsify the medium and to absorb the oils contained in the hydrocarbons sludge. This allowed to stabilize hydrocarbon oils and favored the inductive metabolism of P. aeruginosa. Furthermore, physicochemical and Fourier transform infrared spectroscopy (FTIR) analysis showed that the produced biosurfactants were of rhamnolipid type. They showed promising surfactant properties, such as a strong reduction in the surface tension of water from 72 to 40.52 mN/m, a high reactivity in the culture medium at pH 7, a high osmotolerance up to 150 g/L of salt, and a critical micellar concentration of 21 mg/L.


Assuntos
Pseudomonas aeruginosa , Esgotos , Tensoativos , Ecossistema , Hidrocarbonetos
18.
Zootaxa ; 4732(4): zootaxa.4732.4.3, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32230237

RESUMO

A new species of callianassid mud shrimp is described from outer continental shelf waters of the northwestern Gulf of Mexico, where it appears to commonly live in close association with sediments on or near natural hydrocarbon seeps. Recent genus-level taxonomic revisions of the Callianassidae, based on gene sequence analyses and comparative morphological studies, included specimens representing this new species, assigning it with strong support to the genus Pugnatrypaea Poore et al., 2019. The other known species of this genus are also typically found in offshore waters of continental shelves, but are all restricted in distribution to the Indo-West Pacific and are known from relatively few specimens. Collections of this new Gulf of Mexico representative of the genus are all from slightly deeper waters than for other known congeners, and commonly occur near hydrocarbon seeps, on some occasions being directly associated with sulfidic substrates that include waxy crude oil globules.


Assuntos
Decápodes , Distribuição Animal , Estruturas Animais , Animais , Crustáceos , Golfo do México , Hidrocarbonetos
19.
PLoS One ; 15(3): e0230630, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32218607

RESUMO

Oil pipelines are vulnerable at river crossings since floods can expose and rupture pipes, releasing oil that floats and coats floodplain vegetation. This study investigated the consequences of oil coatings on leaves of cottonwoods (riparian poplars), the predominant trees in floodplain woodlands around the Northern Hemisphere. The study compared conventional crude oil (CO) versus diluted bitumen (dilbit, DB), heavy oil originating from the Alberta oil sands; with petroleum jelly (PJ) as a reference. The treatments increased leaf surface temperatures (Tleaf) in narrowleaf and plains cottonwoods (Populus angustifolia, P. deltoides) and balsam poplars (P. balsamifera) (Control = 21.8°C, PJ = 23.7°C; CO = 26.2°C; DB = 28.1°C; Tair = 25°C). The leaf warming followed stomatal occlusion from the foliar coating, which would reduce transpiration and evaporative cooling, combined with increased solar warming with the darker oils. Tleaf varied across the three cottonwood species, with cooler, narrow, narrowleaf cottonwood leaves; intermediate plains cottonwood leaves; and warmer, darker, balsam poplar leaves (average Tleaf: narrowleaf = 23.8°C, plains = 24.3°C, and balsam = 26.7°C), with similar warming in each species following the different treatments. Across species and treatments, Tleaf was tightly correlated with foliar condition, which assessed turgor versus wilting of leaf blades and petioles, along with leaf necrosis and senescence (r2 = 0.980, narrowleaf; 0.998, plains; 0.852, balsam). This tight association indicates validity of both Tleaf and foliar condition as diagnostic measures. Crude oil and dilbit had similar foliar impacts, and for both, leaf abscission occurred within 2 to 3 weeks. Consequently, following an oil spill, remediation should commence quickly but extending vegetation removal beyond a few weeks would have limited benefit since the contaminated leaves would have abscised.


Assuntos
Hidrocarbonetos/química , Poluição por Petróleo , Petróleo/análise , Populus/fisiologia , Alberta , Inundações , Hidrocarbonetos/toxicidade , Modelos Lineares , Microscopia Eletrônica de Varredura , Petróleo/toxicidade , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/fisiologia , Populus/química , Populus/crescimento & desenvolvimento , Especificidade da Espécie , Temperatura
20.
Medicine (Baltimore) ; 99(12): e19519, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32195954

RESUMO

BACKGROUND: The purposes of this study were to examine the feasibility of using the MyotonPRO digital palpation device in measuring the passive stiffness of gastrocnemius muscle belly and Achilles tendon; to determine between-days test-retest reliability of MyotonPRO; and to evaluate the acute effect of paraffin therapy on stiffness measurements in healthy participants. METHODS: It is a randomized controlled trial. Twenty healthy participants (male, n = 10; female, n = 10; total, n = 20) were recruited to evaluate the passive stiffness of gastrocnemius muscle belly and Achilles tendon. Dominant and nondominant legs were randomly divided into an experimental side (20 cases) and a control side (20 cases). The experimental side received 20 minutes of paraffin therapy. RESULTS: The stiffness of muscle and tendon in the experimental side decreased significantly after paraffin therapy (P < .01), whereas no significant differences in stiffness measurements were found in the control side (P > .05). The passive stiffness of muscle and tendon was positively correlated with the ankle from 30° plantar flexion to10° dorsiflexion for dominant legs. Between-days test-retest reliability in stiffness measurements was high or very high (ICCs were above 0.737). CONCLUSION: Paraffin therapy induces a decrease in the passive stiffness of gastrocnemius muscle belly and Achilles tendon. Furthermore, the MyotonPRO can reliably determine stiffness measurements.


Assuntos
Tendão do Calcâneo/efeitos dos fármacos , Hidrocarbonetos/uso terapêutico , Tono Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Parafina/uso terapêutico , Tendão do Calcâneo/fisiopatologia , Adolescente , Adulto , Articulação do Tornozelo/fisiologia , Feminino , Humanos , Masculino , Músculo Esquelético/fisiopatologia , Modalidades de Fisioterapia/tendências , Amplitude de Movimento Articular/fisiologia , Reprodutibilidade dos Testes , Adulto Jovem
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