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Ginkgo agroforestry practices alter the fungal community structures at different soil depths in Eastern China 全文
2019
Guo, Jing | Wang, Guibin | Wu, Yaqiong | Shi, Yuanbao | Feng, Yu | Cao, Fuliang
Agroforestry practices aim to achieve environmentally friendly land use. Fungi play a primarily role in soil organic carbon and nutrient maintenance, while the response of the soil fungi community to land use changes is little explored. Here, a high-throughput sequencing method was applied to understand the fungal community structure distinction in ginkgo agroforestry systems and adjacent croplands and nurseries. Our results showed that the agroforestry systems achieved better soil fertility and carbon contents. The agroforestry practices significantly altered the composition of soil fungal communities comparing with pure gingko plantation, adjacent cropland, and nursery. The dominant fungal phyla were always Ascomycota and Basidiomycota. The relative abundance of Ascomycota was correlated with the TN and AP, while the abundance of Basidiomycota was negatively correlated with the TN and NN. The soil organic carbon, total nitrogen, and nitrate nitrogen explained 59.80% and 63.36% of the total variance in the fungal community composition in the topsoil and subsoil, and the available phosphorus also played a key role in the topsoil. Considering soil fertility maintenance and fungal community survival and stability, the agroforestry systems achieved better results, and the ginkgo and wheat system was the best among the five planting systems we studied. In the ginkgo and wheat system, applying readily available mineral nitrogen fertilizer either alone or in combination with organic amendments will improve the soil quality and fertility.
显示更多 [+] 显示较少 [-]Exposure to inhalable aerosols and their chemical characteristics from different potential factors in urban office environments 全文
2019
Oh, Hyeon-Ju | Jeong, Na-Na | Sohn, Jong-Ryeul | Roh, Jae-Seung | Kim, Jongbok
Indoor air quality (IAQ) is one of important issues in indoor environment due to exposure to inhalable aerosol which is affected by indoor and outdoor factors. To demonstrate the effect of indoor and outdoor to the IAQ, this study presents three fractions of particulate matter (PM) (PM₂.₅, PM₄, PM₁₀), characterization of I/O ratios for PM under potential indoor (average occupancy) and outdoor factors (Asian dust, rain, wind, and snow days) and evaluation of chemical components in aerosols. In the chemical characteristics of PM, organic carbon (OC), elemental carbon (EC), and trace elements were analyzed in indoors and outdoors. There was no significant difference of respirable aerosol (PM₂.₅ and PM₄) concentration in different indoor environments. The concentration of OC in PM₁₀ was lower in indoor than outdoor in summer and winter seasons, while the concentration of OC in PM₂.₅ was higher in indoor than outdoor. Also, the OC/EC ratios in PM₂.₅ were higher than those in PM₁₀. Further, the ratios of trace elements in PM₂.₅ and PM₁₀ were different at various locations within the building. This study demonstrated that the exposure to PM₂.₅ is greatly affected by outdoor environment. Although there was no difference in inhalable and respirable aerosol concentration at different locations within the building, the impact of outdoor factors is strongly supported by OC/EC ratios and PM₂.₅/PM₁₀ ratios of trace elements. This study shows that chemical components through the HVAC system affected the exposure to the indoor respirable aerosol, which could lead to adverse effect on the indoor air quality.
显示更多 [+] 显示较少 [-]Microplastic distribution in surface sediments along the Spanish Mediterranean continental shelf 全文
2019
Filgueiras, Ana Virginia | Gago, Jesús | Campillo, Juan Antonio | León, Víctor Manuel
Microplastic distribution in surface sediments along the Spanish Mediterranean continental shelf 全文
2019
Filgueiras, Ana Virginia | Gago, Jesús | Campillo, Juan Antonio | León, Víctor Manuel
Microplastics (MPs) are widely recognised as a contaminant of emerging concern in the marine environment. This work provides original data of the presence of MPs in coastal sediments along the Spanish Mediterranean continental shelf. Ten surface sediment samples were collected in order to document baseline microplastic distribution from Algeciras to Barcelona. Microplastics were extracted from bulk sediments by density separation. The number of microplastics per kilogramme of dry weight ranged from 45.9 ± 23.9 MPs/kg d.w. observed at Palma de Mallorca to 280.3 ± 164.9 MPs/kg d.w. noted at Málaga, with an average value of 113.2 ± 88.9 MPs/kg d.w. The lower limit is defined by the pore filter size used (1.2 μm). For all analysed locations, the dominant microplastic type was fibres (82.9%), followed by fragments, and the main colours were transparent and blue. Microplastic size distribution was presented; in the case of fragments, 85% was lower than 0.5 mm, and in the case of fibres, the three studied intervals (0.5–1, 1–2, 2–5 mm) had similar distribution (35, 34 and 31%, respectively). Attending to all available data, no statistically significant relationship (Spearman’s correlation) was found between microplastic average size and distance to the coast, the depth, density population and sediment grain size. Neither relationship was observed between these variables and microplastic concentration using the non-parametric Kruskal-Wallis H test. This study has confirmed the widespread distribution of MPs in surface sediments from the Spanish Mediterranean continental shelf, and these data are useful to define baselines for MPs in the Western Mediterranean region.
显示更多 [+] 显示较少 [-]Microplastic distribution in surface sediments along the Spanish Mediterranean continental shelf 全文
2019
Filgueiras-Rodal, Ana Virginia | Gago, Jesús | Campillo-González, Juan Antonio | León, Víctor Manuel
Microplastics (MPs) are widely recognised as a contaminant of emerging concern in the marine environment. This work provides original data of the presence ofMPs in coastal sediments along the Spanish Mediterranean continental shelf. Ten surface sediment samples were collected in order to document baseline microplastic distribution from Algeciras to Barcelona. Microplastics were extracted from bulk sediments by density separation. The number of microplastics per kilogramme of dry weight ranged from 45.9 ± 23.9 MPs/kg d.w. observed at Palma de Mallorca to 280.3 ± 164.9 MPs/kg d.w. noted at Málaga, with an average value of 113.2 ± 88.9MPs/kg d.w. The lower limit is defined by the pore filter size used (1.2 μm). For all analysed locations, the dominant microplastic type was fibres (82.9%), followed by fragments, and the main colours were transparent and blue. Microplastic size distribution was presented; in the case of fragments, 85% was lower than 0.5 mm, and in the case of fibres, the three studied intervals (0.5–1, 1–2, 2–5 mm) had similar distribution (35, 34 and 31%, respectively). Attending to all available data, no statistically significant relationship (Spearman’s correlation) was found between microplastic average size and distance to the coast, the depth, density population and sediment grain size. Neither relationship was observed between these variables and microplastic concentration using the non-parametric Kruskal-Wallis H test. This study has confirmed the widespread distribution of MPs in surface sediments from the Spanish Mediterranean continental shelf, and these data are useful to define baselines for MPs in the Western Mediterranean region. | This research has been supported by the Spanish Inter-Ministerial Science and Technology Commission through the “IMPACTA” project (CICYT, CTM2013-48194-C3-1-R), “BASEMAN” project (PCIN-2015170-CO2-02), “2-2 ESMARME” project and by the European Union through the European Regional Development Fund (ERDF). | Peer reviewed
显示更多 [+] 显示较少 [-]Structured carbon foam derived from waste biomass: application to endocrine disruptor adsorption 全文
2019
Zbair, Mohamed | Ojala, Satu | Khallok, Hamza | Ainassaari, Kaisu | El Assal, Zouhair | Hatim, Zineb | Keiski, Riitta L. | Bensitel, Mohamed | Brahmi, Rachid
In this paper, a novel structured carbon foam has been prepared from argan nut shell (ANS) was developed and applied in bisphenol A (BPA) removal from water. The results showed that the prepared carbon foam remove 93% of BPA (60 mg/L). The BPA equilibrium data obeyed the Liu isotherm, displaying a maximum uptake capacity of 323.0 mg/g at 20 °C. The calculated free enthalpy change (∆H° = − 4.8 kJ/mol) indicated the existence of physical adsorption between BPA and carbon foam. Avrami kinetic model was able to explain the experimental results. From the regeneration tests, we conclude that the prepared carbon foam has a good potential to be used as an economic and efficient adsorbent for BPA removal from contaminated water. Based on these results and the fact that the developed structured carbon foam is very easy to separate from treated water, it can serve as an interesting material for real water treatment applications.
显示更多 [+] 显示较少 [-]Investigating adsorption mechanism and surface complex formation modeling for aqueous sulfadiazine bonding on Fe/Mn binary oxides 全文
2019
Yu, Jie | Wang, Hongjie | Ji, Qinghua
In aquatic environment, the existence of antibiotics including sulfadiazine (SDZ) has gain a huge attention. It is suggested that hydrous metal oxides have large potential to remove contaminants in water. The SDZ removal capability by ferric and manganese binary oxides (FMBO) was investigated, and the SDZ removal performance was compared with the ferric hydroxide (HFO) and manganese dioxide (HMO). Our results showed that SDZ removal was highly pH-dependent, but pH has less effect on uptake of SDZ on FMBO than that of the other two adsorbents. The surface acidity constant of FMBO was first calculated to be 6.31 and 8.48, respectively. The uptake process was successfully fitted for according to surface complex formation models (SCFM) and the results of modern surface analytical methods, such as FTIR and XPS, were also consistent with the surface complex uptake mechanism. The uptake of SDZ by FMBO ascribed to specific chemical interaction between the aniline group of SDZ and the hydroxyl groups from FMBO.
显示更多 [+] 显示较少 [-]High-throughput analysis of the effects of different fish culture methods on antibiotic resistance gene abundances in a lake 全文
2019
Gu, Jie | Zhang, Li | Wang, Xiaojuan | Lu, Chunya | Liu, Jiayao | Liu, Yue | Li, Lichan | Peng, Jiayuan | Xue, Mingming
Freshwater lakes are important reservoirs for antibiotic resistance genes (ARGs). In this study, we determined the ARG profiles in water samples from Ying Lake, China, using high-throughput quantitative PCR. The high prevalence of ARGs suggested significant pollution with ARGs in the study area, where the ARG diversity and abundance were greater in an area with box-type fish farming than an area with fenced fish farming. Network analysis indicated the widespread co-occurrence of ARGs and mobile genetic elements. cphA-01, blalMP02, and blaCMY202 were identified as adequate indicator genes for estimating the total ARG abundances. Redundancy analysis indicated that changes in the microbial communities caused by variations in the physicochemical parameters with different fish culture methods mainly determined the ARGs in the lake system. Thus, analyzing the factors that affect ARGs provided novel insights into the mechanisms responsible for the maintenance and propagation of ARGs in a lake.
显示更多 [+] 显示较少 [-]Field investigation of temporal variation of volatile organic compounds at a landfill in Hangzhou, China 全文
2019
Wang, Qiao | Zuo, Xinru | Xia, Min | Xie, Haijian | He, Feiyu | Shen, Siliang | Bouazza, Abdelmalek | Zhu, Lili
Variation of volatile organic compound (VOC) concentration and composition in an active landfill were monitored by a developed static chamber for 2 years. The landfill gas from 82 sampling points including 70 points on working face, 8 points on geomembrane (GMB), and 4 points on final cover were analyzed for VOCs by GC-MS. Twenty-eight types of VOCs were detected, including terpenes, sulfur compounds, aromatics, hydrocarbon, oxygenated compounds, aldehyde compounds, and halogenated compounds. Terpenes were the dominant VOCs recorded in the spring, autumn, and winter seasons, whereas sulfur compounds dominated in the summer season. Limonene, ethyl alcohol, and acetone were identified as the main VOCs emitted from the waste working face of the landfill. Limonene dominated the terpenes with a maximum concentration of 43.29 μg m⁻³ in the autumn season. Limonene was also the dominant VOC escaping from the defects of geomembrane temporary cover reaching an average concentration 38 μg m⁻³. The defects of geomembranes can be a great emission source of VOCs. Emission rate of limonene was 2.24 times higher than that on the working face. VOC concentrations on the final cover can be 166 times less than those obtained on the working face. VOC emitted from the landfill did not represent a health threat for human health. However, concentrations of methyl mercaptan and ethanethiol on the working face were 3.4–22.8 times greater than their odor threshold, which were the main compounds responsible for odor nuisance. Results obtained from CALPUFF model indicated that methyl mercaptan and ethanethiol would not be a nuisance for the residents around the landfill. However, these compounds are harmful to the workers on the landfill.
显示更多 [+] 显示较少 [-]No evidence of the role of early chemical exposure in the development of β-cell autoimmunity 全文
2019
Salo, Harri M. | Koponen, Jani | Kiviranta, Hannu | Rantakokko, Panu | Honkanen, Jarno | Härkönen, Taina | Ilonen, Jorma | Virtanen, Suvi M. | Tillmann, Vallo | Knip, Mikael | Vaarala, Outi
Exposure to environmental chemicals can modulate the developing immune system, but its role in the pathogenesis of type 1 diabetes is largely unexplored. Our objective was to study the levels of circulating concentrations of environmental pollutants during the first years of life and their associations with the later risk of diabetes-predictive autoantibodies. From two birth-cohort studies including newborn infants with HLA-conferred susceptibility to type 1 diabetes (FINDIA and DIABIMMUNE), we identified case children with at least one biochemical diabetes-associated autoantibody (n = 30–40) and from one to four autoantibody-negative controls per each case child matched for age, gender, diabetes-related HLA-risk, delivery hospital, and, in FINDIA, also dietary intervention group. Plasma levels of 13 persistent organic pollutants and 14 per- and polyfluorinated substances were analyzed in cord blood and plasma samples taken at the age of 12 and 48 months. Both breastfeeding and the geographical living environment showed association with circulating concentrations of some of the chemicals. Breastfeeding-adjusted conditional logistic regression model showed association between decreased plasma HBC concentration at 12-month-old children and the appearance of diabetes-associated autoantibodies (HR, 0.989; 95% Cl, 0.978–1.000; P = 0.048). No association was found between the plasma chemical levels and the development of clinical type 1 diabetes. Our results do not support the view that exposure to the studied environmental chemicals during fetal life or early childhood is a significant risk factor for later development of β-cell autoimmunity and type 1 diabetes.
显示更多 [+] 显示较少 [-]Evaluation of efficacy of the essential oil from Ostericum viridiflorum (Turcz.) Kitagawa in control of stored product insects 全文
2019
Zhang, Hai Ming | Guo, Shan Shan | Fan, Bin | Du, Shu Shan | Wang, Yongyan | Deng, Zhi Wei
The natural and ecologically safe control of stored product insects has gained considerable attention in modern society. In this study of further searching for botanical pesticides from wild-growing plant, the contact toxicity and repellency towards Tribolium castaneum and Liposcelis bostrychophila were assessed for the essential oil (EO) from Ostericum viridiflorum. The EO was distilled from aboveground parts of O. viridiflorum and checked by gas chromatography-mass spectrometry. Twenty-two compounds were identified and the main components were β-caryophyllene (24.3%), α-humulene (21.0%), apiol (10.2%), and carotol (2.5%). For bioactivity tests, results indicated that the EO and its two main compounds (β-caryophyllene and α-humulene) all showed potent contact toxicity towards L. bostrychophila with LD₅₀ values of 44.52 μg/cm², 74.11 μg/cm², and 118.56 μg/cm², respectively. The EO and the two main compounds also exhibited comparable repellency towards T. castaneum and L. bostrychophila. The results evidenced the EO of O. viridiflorum aboveground parts and its major compounds could be considered for the development of eco-friendly botanical insecticides and repellents in controlling stored product insects.
显示更多 [+] 显示较少 [-]Efficient photocatalytic methylene blue degradation by Fe3O4@TiO2 core/shell linked to graphene by aminopropyltrimethoxysilane 全文
2019
Nazari, Yousef | Salem, Shiva
In the present article, Fe₃O₄@TiO₂ core/shell (FT) linked to graphene was fabricated by sol–gel technique as a photocatalyst and was employed for the solar degradation of cationic methylene blue (MB) in aqueous solution. The prepared core/shells were linked to graphene oxide (FTGO) and reduced graphene oxide (FTRGO) via embedding into 3-aminopropyltrimethoxysilane (APS). The structure of this magnetic composition was characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and BET surface area measurements. The significance of the composite structure in photocatalytic degradation was spectrophotometrically tested by blending the obtained powders with wastewater containing methylene blue under solar irradiation. The appropriate dosage of APS to link the Fe₃O₄@TiO₂ core/shell onto GO and RGO surfaces was determined to be 1 ml per gram of FT. The kinetic studies were performed to investigate the effects of different parameters, such as composition structure, APS dosage, and repeatability. Kinetic data are well fitted by a first-order model with a high correlation coefficient. Regardless of the prominent advantage of composites in magnetic powder separation, the Fe₃O₄@TiO₂ core/shell linked to graphene oxide is an efficient composite in comparison to FTRGO for the dye degradation without losing the original activity and stability.
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