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The effect of polystyrene plastics on the toxicity of triphenyltin to the marine diatom Skeletonema costatum—influence of plastic particle size Texto completo
2019
Yi, Xianliang | Wang, Jianfeng | Li, Zhaochuan | Zhang, Zherui | Chi, Tongtong | Guo, Miao | Li, Wentao | Zhou, Hao
The effect of polystyrene (PS) particles on the toxicity of triphenyltin (TPT) to the marine diatom Skeletonema costatum was investigated. The 0.1-μm PS particles attached to the cell walls of S. costatum but did not cause adverse effects on the growth of the diatom. The adsorption of TPT to PS particles was negligible in seawater systems, but the presence of 0.1-μm PS significantly reduced the bioavailable concentrations of TPT in f/2-Si medium, indicating a potential three-way interaction between TPT, PS particles, and components of f/2-Si medium. The adsorption of TPT to PS of smaller size (i.e., 0.1 μm) was stronger than that of PS of larger size (i.e., 5 μm), which was probably attributed to larger surface areas of smaller PS particles. The presence of PS could reduce the toxicity of TPT. IC₅₀ values of TPT increased from 0.56 to 0.85 and 0.71 μg/L at the presence of 20 mg/L 0.1-μm PS and 5-μm PS, respectively. The overall results of this study profiled the combined toxic effects of PS and TPT on marine phytoplankton species and highlighted the difference in adsorption of organic pollutants by microplastics in different ambient mediums.
Mostrar más [+] Menos [-]Fate of Lu(III) sorbed on 2-line ferrihydrite at pH 5.7 and aged for 12 years at room temperature. I: insights from ICP-OES, XRD, ESEM, AsFlFFF/ICP-MS, and EXAFS spectroscopy Texto completo
2019
Finck, Nicolas | Bouby, Muriel | Dardenne, Kathy
Two-line ferrihydrite (2LFh) was aged for 12 years under ambient conditions and sheltered from light in the presence of Lu(III) used as surrogate for trivalent actinides. 2LFh aging produced hematite rhombohedra with overgrown acicular goethite particles. Analysis of the homogeneous suspension by asymmetrical flow field-flow fractionation (AsFlFFF) coupled to ICP-MS indicated that particles have a mean hydrodynamic diameter of about 140 nm and the strong correlation of the Fe and Lu fractograms hinted at a structural association of the lanthanide with the solid phase(s). Unfortunately, recoveries were low and thus results cannot be considered representative of the whole sample. The suspension was centrifuged and X-ray absorption spectroscopy (XAS) at the Lu L₃-edge on the settled particles indicated that Lu(III) is sixfold coordinated by oxygen atoms, pointing to a retention by structural incorporation within particles. This result is consistent with AsFlFFF results on the same suspension without centrifugation. The detection of next nearest Fe and O atoms were consistent with the structure of goethite, ruling out incorporation within hematite. After centrifugation of the suspension, only nanoparticulate needle-like particles, very likely goethite, could be detected in the supernatant by ESEM. AsFlFFF data of the supernatant were comparable to that obtained for the homogeneous suspension, whereas XAS indicated that Lu(III) is predominantly present as dissolved species in the supernatant. Results from both techniques can be interpreted as a major fraction of Lu present as aqueous ions and a minor fraction as structurally incorporated. Findings from this study are corroborated by STEM-HAADF data and results from DFT calculations in a companion paper.
Mostrar más [+] Menos [-]Evaluation of emerging biomarkers of renal damage and exposure to aflatoxin-B1 in Mexican indigenous women: a pilot study Texto completo
2019
Díaz de León Martínez, Lorena | Díaz-Barriga, Fernando | Barbier, Olivier | Ortíz, Dora Linda Guzmán | Ortega-Romero, Manolo | Pérez Vázquez, Francisco | Flores Ramírez, Rogelio
Aflatoxins (AFs) are mycotoxins produced by Aspergillus parasiticus and Aspergillus flavus which frequently contaminate maize. These compounds are considered toxic, especially AFB₁ which has been classified as a human carcinogen, due to its relationship with the generation of hepatocellular carcinoma. Studies in vivo, in animal models, prove that chronic consumption of AFB₁ has an association with renal adverse effects, but evidence in humans is scarce. Therefore, the main objective of this research was to conduct a pilot study to evaluate the correlation between exposure to AFB₁ and early-stage renal damage in indigenous women of San Luis Potosí, Mexico. Exposure to AFB₁ was measured through the biomarker AFB₁-lysine and renal damage through kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and cystatin-C (Cys-C). AFB₁-Lys was measured by HPLC-FLD. The method was validated with a correlation coefficient of 0.99 and limit of detection and quantification of 3.5 and 4.7 pg mL⁻¹, respectively. Levels of NGAL, KIM-1, and Cys-C were determined (median (P25–P75), 5.96 (3.16–15.91), 0.137 (0.137–0.281), and 18.49 (5.76–29.57) ng mL⁻¹, respectively). Additionally, glomerular filtration rate (GFR) (83.3 (59.8–107.4) mL/min/1.73 m²) and serum creatinine (SCr) (0.88 (0.72–1.22) mg dL⁻¹) were obtained. The median concentrations for AFB₁-Lys were 2.08 (1.89–5.8) pg mg⁻¹ of albumin. Statistically significant correlations between AFB₁-Lys/KIM-1 (Rho = 0.498, p = 0.007) and AFB₁/Cys-C (Rho = 0.431, p = 0.014) were found. Our results indicate that women are exposed to AFB₁, due to the fact that the AFB₁-Lys biomarker was found in a high percentage of the study population (83%). In addition, the results of exposure to AFB₁ show a strong significant correlation between KIM-1 and Cys-C that may indicate the toxic renal effect. These results are alarming because of the high toxicity of this compound and require adequate intervention to reduce AFB₁ exposure in these populations.
Mostrar más [+] Menos [-]Sub-lethal effects induced by a mixture of different pharmaceutical drugs in predicted environmentally relevant concentrations on Lithobates catesbeianus (Shaw, 1802) (Anura, ranidae) tadpoles Texto completo
2019
do Amaral, Diogo Ferreira | Montalvão, Mateus Flores | de Oliveira Mendes, Bruna | da Costa Araújo, Amanda Pereira | de Lima Rodrigues, Aline Sueli | Malafaia, Guilherme
The increasing consumption of medications by humans has negative effects such as the increased disposal of these compounds in the environment. Little is known about how the disposal of a “drug mix” (DM) in aquatic ecosystems can affect their biota. Thus, we evaluated whether the exposure of Lithobates casteibeianus tadpoles to a DM composed of different medication classes (antibiotic, anti-inflammatory, antidepressant, anxiolytic, analgesic, and antacid drugs)—at environmentally relevant concentrations—may change their oral morphology, trigger behavioral disorders, and have mutagenic effects on erythrocyte cells. Based on our data, animals exposed to the DM showed changes in mandibular sheath pigmentation, dentition, and swimming activity, as well as atypical behavior in the social aggregation test [with co-specific and interspecific (Physalaemus cuvieri) individuals] and antipredatory defensive response deficit (chemical stimulus from Odonata larvae), after 15 exposure days. The mutagenic analysis revealed higher frequency of nuclear abnormalities in the erythrocytes of tadpoles exposed to the DM (e.g., multilobulated, blebbed, kidney-shaped, notched nucleus, binuclear, and micronucleated erythrocytes). Given the chemical complexity of the DM, we assumed that several organic functions may have been affected, either by the isolated, synergistic, antagonistic, or additive action of DM compounds. Finally, our study confirms the toxicological potential of DM in L. catesbeianus tadpoles, with emphasis to impacts that can affect the fitness of individuals and their natural populations. Thus, we suggest that more attention should be given to the disposal of medications in the environment and reinforce the need of improving water and sewage treatment systems.
Mostrar más [+] Menos [-]Pyrolyzed municipal sewage sludge ensured safe grain production while reduced C emissions in a paddy soil under rice and wheat rotation Texto completo
2019
Shao, Qianqian | Ju, Yanyan | Guo, Wenjie | Xia, Xin | Bian, Rongjun | Li, Lianqing | Li, Wenjian | Liu, Xiaoyu | Zheng, Jufeng | Pan, Genxing
Safe recycling of the growing amounts of municipal sewage sludge containing toxic metals had been critically challenged with the fast urbanization. In this study, we investigated soil amendment of municipal wastewater treatment (MSS) converted biochar for its recycling in agricultural soils. In a field experiment, unpyrolyzed (USS) and pyrolyzed municipal sewage sludge (PSS) was amended at 20 t ha⁻¹ on dry base to a rice paddy before rice plantation, with a control without amendment. Grain yield and emission of non-CO₂ potent greenhouse gases were examined as well as topsoil metal mobility and plant uptake determined throughout a rice-wheat rotation year. Compared to USS treatment, addition of PSS caused a significantly increased grain yield of rice by 35% but no change in grain yield of wheat following the rice season. No distinct difference was observed in grain concentration of major nutrients of N, P, and K between USS and PSS treatments. Compared to USS treatment, PSS treatment reduced CH₄ emissions by 91.6% from soil and by 78.5% from ecosystem during rice-growing season. Whereas, PSS treatment led to a reduction of ecosystem N₂O emissions by 70.8% relative to USS treatment during wheat-growing season. While both USS and PSS treatments slightly but insignificantly increased soil total content of heavy metals, PSS treatment reduced CaCl₂-extractable Cd pool by 33~40% over USS treatment. Grain contents of Cd and Pb and Cd/Zn were markedly reduced under PSS over USS, without exceeding the Chinese state guideline limit. Carbon emission intensity was considerably (by over 20%) reduced for soil and ecosystem but unchanged for wheat soil, under PSS over USS. Thus, soil amendment of pyrolyzed sewage sludge could be a measure for climate smart soil and for safe grain production in rice agriculture. It deserves further study if repeated amendment could exert sustainable impacts on soil health and food security in the paddy.
Mostrar más [+] Menos [-]Long-term responses of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) to the contamination of light soils with diesel oil Texto completo
2019
Bęś, Agnieszka | Warmiński, Kazimierz | Adomas, Barbara
Research into trees plays a very important role in evaluations of soil contamination with diesel oil. Trees are ideal for reclaiming contaminated soils because their large biomass renders them more resistant to higher concentrations of pollutants. In the literature, there is a general scarcity of long-term studies performed on trees, in particular European beeches. The aim of this study was to evaluate the responses of Scots pines and European beeches grown for 8 years on soil contaminated with diesel oil. Selected morphological and physiological parameters of trees were analyzed. The biomass yield of Scots pines was not significantly correlated with increasing concentrations of diesel oil, but it was more than 700% higher than in European beeches. Scots pines were taller and had a larger stem diameter than European beeches during the 8-year study. The diameter of trees grown on the most contaminated soil was reduced 1.5-fold in Scots pines and more than twofold in European beeches. The length of Scots pine needles from the most contaminated treatment decreased by 50% relative to control needles. The shortest needles were heaviest. The fluctuating asymmetry (FA) of needle length was highest in Scots pines grown on the most contaminated soil, whereas the reverse was noted in the FA of needle weight. Diesel oil decreased the concentrations of chlorophylls a and b, total chlorophyll, and carotenoids. The Fv/Fm ratio of needles and leaves was influenced by the tested concentrations of diesel oil. The results of the study indicate that the Scots pine better adapts (grows more rapidly and produces higher biomass) to long-term soil contamination with diesel oil than the European beech. In European beeches, growth inhibition and leaf discoloration (a decrease in chlorophyll content) were observed already after the first year of the experiment, which indicates that 1-year-old seedlings of European beech are robust bioindicators of soil contamination with diesel oil.
Mostrar más [+] Menos [-]Simultaneous removal of SO2 and NO by FeII(EDTA) solution: promotion of Mn powder and mechanism of reduction Texto completo
2019
Duo, Yankai | Wang, Xiaoping | He, Jinjia | Zhang, Shihan | Pan, Hua | Chen, Jianmeng | Chen, Jun
The effect of Mn powder addition on the simultaneous removal of SO₂ and NO coupled with Feᴵᴵ(EDTA) absorption was investigated in this work. In the NO absorption system with Feᴵᴵ(EDTA), SO₂ reduced Feᴵᴵ(EDTA)-NO to Feᴵᴵ(EDTA) with a reduction efficiency reaching 88.5% under the conditions of 4000 mg/m³ SO₂, pH 8.0, 44 °C, and the flow rate of 1.2 L/min within 60 min. Introducing 0.1 M Mn powder with SO₂ increased the Feᴵᴵ(EDTA)-NO reduction efficiency to 96.8% within 5 min. SO₂ was also removed by reducing Feᴵᴵ(EDTA)-NO and converted into SO₄²⁻ at a removal efficiency of 100%. After adding Mn powder, NO was removed through the following reaction: [Formula: see text]. Mn powder functioned as a reductant to regenerate the absorption of solution, and the coordinated NO in Feᴵᴵ(EDTA)-NO was reduced to NH₄⁺. The resource utilization rate of N reached approximately 77.2%. The integrated technology is a potential solution for flue gas treatment in industrial sectors with coal-fired power plants and industrial boiler. Graphical abstract
Mostrar más [+] Menos [-]Mapping the research of energy subsidies: a bibliometric analysis Texto completo
2019
Wang, Zhen | Wang, Yanwen | Peng, Sha | Niu, Beibei | Cui, Can | Wu, Junyi
A review of energy subsidy research from a bibliometric perspective was conducted. Based on the bibliometric method, a statistical analysis of energy subsidy–related publications from 1997 to 2016 was undertaken using the Science Citation Index (SCI) and Social Science Citation Index (SSCI) databases. A total of 1182 publications were retrieved, with a significant increase in the number of publications observed after 2006. The majority of these publications were within the disciplines of Energy & Fuels and Environmental Science & Ecology. Although the USA and China contributed the most papers, authors from 96 countries were involved in the various studies. The USA was the center of global collaborations, while other countries/territories mainly conducted bilateral or regional collaborations in their research activities. Five of the top 11 most productive institutes were from China, followed by the USA. The frequency of collaborations among institutes was relatively low. However, the institute–keyword 2-mode network showed that institutes had great potential to cooperate on a number of common topics. Five major themes were identified from the co-keywords analysis: general renewable energy research, bio-energies, sustainability, subsidies, and welfare. The findings, as a complement to previous conventional reviews, will be useful in future energy subsidy research.
Mostrar más [+] Menos [-]Enhanced nitrogen removal of coal pyrolysis wastewater with low COD to nitrogen ratio by partial nitrification-denitrification bioprocess assisted with polycaprolactone Texto completo
2019
Zhang, Zhengwen | Xu, Chunyan | Zhong, Dan | Han, Yuxing | Han, Hongjun | Zheng, Mengqi | Zhu, Hao
The purpose of this study is to investigate the enhancement of polycaprolactone (PCL) on total nitrogen (TN) removal of coal pyrolysis wastewater (CPW) with low COD to nitrogen ratio by partial nitrification-denitrification bioprocess (PNDB) in one single reactor. With the innovative combination of PCL and PNDB, the TN removal efficiency in the experimental reactor (signed as R1) was 10.21% higher than control reactor (R2). Nitrite accumulation percentage (NAP) in R1 was 82.02%, which was 17.49% higher than R2 at the dissolved oxygen (DO) concentration of 0.9–1.5 mg/L, for the reason that the extra DO was consumed by PCL biodegradation at the aerobic period. Gel permeation chromatography (GPC) results demonstrated that organics with the molecular weight of 185 Da, which could serve as additional carbon sources for denitrifiers, were generated during the PCL hydrolysis process at the anoxic period. PCL was hydrolyzed by extracellular enzymes with the break of the ester bond which was confirmed by FT-IR spectrometer. Microbial community analysis revealed that Ferruginibacter was the dominant hydrolysis bacteria in R1. Nitrosomonas were the main ammonium-oxidizing bacteria (AOB) and Hyphomicrobium were the denitrifiers in this study.
Mostrar más [+] Menos [-]Prediction of O3 in the respiratory system of children using the artificial neural network model and with selection of input based on gamma test, Ahvaz, Iran Texto completo
2019
Ghaedrahmat, Zeinab | Vosoughi, Mehdi | Tahmasebi Birgani, Yaser | Neisi, Abdolkazem | Goudarzi, Gholamreza | Takdastan, Afshin
In recent years, concerns over the issue of air pollution have increased as one of the significant environmental and health problems. Air pollutants can be toxic or harmful to the life of plants, animals, and humans. Contrast to primary pollutants, ozone is a secondary pollutant that is produced by the reaction between primary precursors in the atmosphere. The average of air pollutant data was compiled for the purpose of analyzing their correlation with the pulmonary function of students and the FENO biomarker from the air pollutants of the Environmental Protection Agency. According to the average of 3 days, the concentration of ozone in the (S₃) region was higher than the other regions, and this level was significantly different from the ANOVA test (p < 0.05). The results of artificial neural network modeling for three particular combinations in the cold season, two hidden layers with 9 and 12 neurons, with R² = 0.859 and in the warm season, layer with 13 neurons, with R² = 0.74, showed the best performance.
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