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Antibiotic and heavy-metal resistance of Vibrio parahaemolyticus isolated from fresh shrimps in Shanghai fish markets, China
2016
He, Yu | Jin, Lanlan | Sun, Fengjiao | Hu, Qiongxia | Chen, Lanming
Vibrio parahaemolyticus is a causative agent of human serious seafood-borne gastroenteritis disease and even death. Shrimps, often eaten raw or undercooked, are an important reservoir of the bacterium. In this study, we isolated and characterized a total of 400 V. parahaemolyticus strains from commonly consumed fresh shrimps (Litopenaeus vannamei, Macrobrachium rosenbergii, Penaeus monodon, and Exopalaemon carinicauda) in Shanghai fish markets, China in 2013–2014. The results revealed an extremely low occurrence of pathogenic V. parahaemolyticus carrying two major toxic genes (tdh and trh, 0.0 and 0.5 %). However, high incidences of antibiotic resistance were observed among the strains against ampicillin (99 %), streptomycin (45.25 %), rifampicin (38.25 %), and spectinomycin (25.50 %). Approximately 24 % of the strains derived from the P. monodon sample displayed multidrug resistant (MDR) phenotypes, followed by 19, 12, and 6 % from the E. carinicauda, L. vannamei, and M. rosenbergii samples, respectively. Moreover, tolerance to heavy metals of Cr³⁺ and Zn²⁺ was observed in 90 antibiotic resistant strains, the majority of which also displayed resistance to Cu²⁺ (93.3 %), Pb²⁺ (87.8 %), and Cd²⁺(73.3 %). The pulsed-field gel electrophoresis (PFGE)-based genotyping of these strains revealed a total of 71 distinct pulsotypes, demonstrating a large degree of genomic variation among the isolates. The wide distribution of MDR and heavy-metal resistance isolates in the PFGE clusters suggested the co-existence of a number of resistant determinants in V. parahaemolyticus population in the detected samples. This study provided data in support of aquatic animal health management and food safety risk assessment in aquaculture industry.
显示更多 [+] 显示较少 [-]Variation of physicochemical properties of drinking water treatment residuals and Phoslock® induced by fulvic acid adsorption: Implication for lake restoration
2016
Wang, Changhui | Jiang, He-Long | Xu, Huacheng | Yin, Hongbin
The use of phosphorus (P) inactivating agents to reduce internal P loading from sediment for lake restoration has attracted increasing attention. Reasonably, the physicochemical properties of P inactivating agents may vary with the interference of various environmental factors, leading to the change of control effectiveness and risks. In this study, the effect of fulvic acid (FA) adsorption on the properties of two agents, drinking water treatment residuals (DWTRs) and Phoslock®, was investigated. The results showed that after adsorption, there was little change for the main structures of DWTRs and Phoslock®, but the thermostability of Phoslock®, as well as the particle size and settleability of the two agents decreased. The specific surface area and pore volume of DWTRs also decreased, while those of Phoslock® increased. Further analysis indicated that aluminum and iron in DWTRs were stable during FA adsorption, but a substantial increase of lanthanum release from Phoslock® was observed, in particular at first (P < 0.01). Moreover, the P immobilization capability of DWTRs had little change after FA adsorption, while the capability of Phoslock® after FA adsorption decreased in solutions (P < 0.001) and sediments (P < 0.1); interestingly, from the view of engineering application, the performance of Phoslock® was not substantially affected. Overall, each P inactivating agent had its own particular responses of the physicochemical properties to environment factors, and detailed investigations on the applicability of each agent were essential before practical application.
显示更多 [+] 显示较少 [-]Distribution and sources of oxygenated non-hydrocarbons in topsoil of Beijing, China
2016
Zhang, Zhihuan | Wan, Tiantian | Peng, Xuyang | He, Guangxiu | Liu, Yu | Zeng, Li
The oxygenated non-hydrocarbon compounds are widely distributed in soil. To investigate the distribution and origin of these compounds in topsoil of Beijing, their contents and compositions were measured in topsoil from 62 sites in Beijing. The research results showed that oxygenated non-hydrocarbons were composed primarily of C₆∼C₂₈ n-fatty acids, C₁₂∼C₂₈ n-fatty alcohols, n-fatty acid methyl esters, phthalates, sterols, and dehydroabietic acid in the topsoil of Beijing. The contents and compositions of these compounds varied with the sampling site. The concentrations of n-fatty acids and phthalate esters were the highest at all sites, followed by sterols, n-fatty acid methyl esters, fatty alcohols, and dehydroabietic acid in order. The n-fatty acids had a main peak of C₁₆, followed by C₁₈. An odd or even carbon number predominance was not observed in the low-molecular-weight n-fatty acids, indicating a fossil fuel or organic matter source. However, some high-molecular-weight n-fatty acids with an even carbon predominance may derive from a biomass. The n-fatty alcohols showed a main peak of C₂₂ and were predominated by an even carbon number, suggesting plant, microbial, or other natural origins. Phthalates, including diethyl phthalate (DEP), diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), diethylhexyl phthalate (DEHP), and dimethylphthalate (DMP), were detected. The content of phthalate esters was higher in the samples collected from dense human activity areas. The concentrations of DBP, DEHP, and DIBP were relatively high, indicating an anthropogenic source. The sterols (predominantly β-sitosterol) originated from biological sources, especially plants. The n-fatty acid methyl esters and dehydroabietic acid in topsoil showed apparent even carbon predominance with the former mainly derived from microorganisms or plants and the latter from cork combustion products.
显示更多 [+] 显示较少 [-]Biosorption of alpacide blue from aqueous solution by lignocellulosic biomass: Luffa cylindrica fibers
2016
Kesraoui, Aida | Moussa, Asma | Ali, Ghada Ben | Seffen, Mongi
The aim of the present work is to develop an effective and inexpensive pollutant-removal technology using lignocellulosic fibers: Luffa cylindrica, for the biosorption of an anionic dye: alpacide blue. The influence of some experimental parameters such as pH, temperature, initial concentration of the polluted solution, and mass of the sorbent L. cylindrica on the biosorption of alpacide blue by L. cylindrica fibers has been investigated. Optimal parameters for maximum quantity of biosorption dye were achieved after 2 h of treatment in a batch system using an initial dye concentration of 20 mg/L, a mass of 1 g of L. cylindrica fibers, and pH 2. In these conditions, the quantity of dye retained is 2 mg/g and the retention rate is 78 %. Finally, a mathematical modeling of kinetics and isotherms has been used for mathematical modeling; the model of pseudo-second order is more appropriate to describe this phenomenon of biosorption. Concerning biosorption isotherms, the Freundlich model is the most appropriate for a biosorption of alpacide blue dye by L. cylindrica fibers.
显示更多 [+] 显示较少 [-]Assessment of trace metal air pollution in Paris using slurry-TXRF analysis on cemetery mosses
2016
Natali, Marco | Zanella, Augusto | Rankovic, Aleksandar | Banas, Damien | Cantaluppi, Chiara | Abbadie, Luc | Lata, Jean -Christophe
Mosses are useful, ubiquitous accumulation biomonitors and as such can be used for biomonitoring surveys. However, the biomonitoring of atmospheric pollution can be compromised in urban contexts if the targeted biomonitors are regularly disturbed, irregularly distributed, or are difficult to access. Here, we test the hypothesis that cemeteries are appropriate moss sampling sites for the evaluation of air pollution in urban areas. We sampled mosses growing on gravestones in 21 urban and peri-urban cemeteries in the Paris metropolitan area. We focused on Grimmia pulvinata (Hedwig) Smith, a species abundantly found in all studied cemeteries and very common in Europe. The concentration of Al, As, Br, Ca, Ce, Cl, Cr, Cu, Fe, K, Mn, Ni, V, P, Pb, Rb, S, Sr, Ti, and Zn was determined by a total reflection X-ray fluorescence technique coupled with a slurry sampling method (slurry-TXRF). This method avoids a digestion step, reduces the risk of sample contamination, and works even at low sample quantities. Elemental markers of road traffic indicated that the highest polluted cemeteries were located near the highly frequented Parisian ring road and under the influence of prevailing winds. The sites with the lowest pollution were found not only in the peri-urban cemeteries, adjoining forest or farming landscapes, but also in the large and relatively wooded cemeteries located in the center of Paris. Our results suggest that (1) slurry-TXRF might be successfully used with moss material, (2) G. pulvinata might be a good biomonitor of trace metals air pollution in urban context, and (3) cemetery moss sampling could be a useful complement for monitoring urban areas. Graphical abstract We tested the hypothesis that cemeteries are appropriate moss sampling sites for the evaluation of air pollution in urban areas. We sampled 110 moss cushions (Grimmia pulvinata) growing on gravestones in 21 urban and peri-urban cemeteries in the Paris metropolitan area. The concentration of 20 elements in mosses was determined by a total reflection X-ray fluorescence technique coupled with a slurry sampling method. Statistical analysis revealed that: - Urbanized Parisian areas crossed by traffic roads have the highest polluted cemeteries with a strong influence of main wind direction on the distribution of air pollutants - As expected, small cemeteries with low tree density were heavily polluted - Less obvious, large green spaces such as large cemeteries (Père Lachaise, Montmartre, Montparnasse) in the center of a dense metropolis like Paris present the same level of atmospheric trace metal pollution as cemeteries in less urbanized areas or nearing a very large forest. This suggests that even in densely urbanized areas, there is more spatial variability in pollution distribution than usually assumed and that large urban areas with low traffic and green filters such as trees are likely to intercept air pollutants
显示更多 [+] 显示较少 [-]Assessment of the environmental significance of nutrients and heavy metal pollution in the river network of Serbia
2016
Dević, Gordana | Sakan, Sanja | Đorđević, Dragana
In this paper, the data for ten water quality variables collected during 2009 at 75 monitoring sites along the river network of Serbia are considered. The results are alarming because 48 % of the studied sites were contaminated by Ni, Mn, Pb, As, and nutrients, which are key factors impairing the water quality of the rivers in Serbia. Special attention should be paid to Zn and Cu, listed in the priority toxic pollutants of US EPA for aquatic life protection. The employed Q-model cluster analysis grouped the data into three major pollution zones (low, moderate, and high). Most sites classified as “low pollution zones” (LP) were in the main rivers, whereas those classified as “moderate and high pollution zones” (MP and HP, respectively) were in the large and small tributaries/hydro-system. Principal component analysis/factor analysis (PCA/FA) showed that the dissolved metals and nutrients in the Serbian rivers varied depending on the river, the heterogeneity of the anthropogenic activities in the basins (influenced primarily by industrial wastewater, agricultural activities, and urban runoff pollution), and natural environmental variability, such as geological characteristics. In LP dominated non-point source pollution, such as agricultural and urban runoff, whereas mixed source pollution dominated in the MP and HP zones. These results provide information to be used for developing better pollution control strategies for the river network of Serbia.
显示更多 [+] 显示较少 [-]Risk assessment and vertical distribution of thallium in paddy soils and uptake in rice plants irrigated with acid mine drainage
2016
Huang, Xuexia | Li, Ning | Wu, Qihang | Long, Jianyou | Luo, Dinggui | Zhang, Ping | Yao, Yan | Huang, Xiaowu | Li, Dongmei | Lu, Yayin | Liang, Jianfeng
The objective of this paper is to assess the influence of irritating paddy fields with acid mine drainage containing thallium (Tl) to rice plant-soil system and potential health risks for local residents. Vertical distribution of Tl, pH, organic matter (OM), and cation exchange capacity (CEC) in 24 paddy soil profiles around Yunfu pyrite mine area was investigated. Rice plant samples were collected from the corresponding soil sampling site. The results showed that Tl concentrations in paddy soils at 0–60 cm depth range from 3.07 to 9.42 mg kg⁻¹, with a mean of 5.74 mg kg⁻¹, which were significantly higher than the background value of soil in China (0.58 mg kg⁻¹). On the whole, Tl contents in paddy soil profiles increased quickly with soil depth from 0 to 30 cm and decreased slowly with soil depth from 30 to 60 cm. The soil Tl content was significant negatively correlated with soil pH. The mean content of Tl in the root, stem, leaf, and rice was 4.36, 1.83, 2.74, and 1.42 mg kg⁻¹, respectively, which exceeded the proposed permissible limits for foods and feedstuffs in Germany. The Tl content in various tissues of the rice plants followed the order root > leaf > stem (rice), which suggested that most Tl taken up by rice plants retained in the root, and a little migrated to the leaf, stem, and rice. Correlation analysis showed that Tl content in root was significant positively correlated with Tl content in leaf and rice. The ranges of hazard quotient (HQ) values were 4.08∼24.50 and 3.84∼22.38 for males and females, respectively. Males have higher health risk than females in the same age group. In childhood age groups (2 to <21 years) and adult age groups (21 to <70 years), the highest health risk level was observed in the 11 to 16 age group and 21 to 50 age group, respectively. The findings indicated that regular irrigation with Tl-bearing acid mine drainage led to considerable contamination of Tl in paddy soil and rice plant. Local government should take various measures to treat Tl contamination, especially the tailings.
显示更多 [+] 显示较少 [-]Combined promoting effects of low-Pd-containing and Cu-doped LaCoO3 perovskite supported on cordierite for the catalytic combustion of benzene
2016
Chen, Y. W. | Li B., | Niu, Q. | Li, L. | Kan, J. W. | Zhu, S. M. | Shen, S. B.
The catalytic activities for benzene oxidation and resistance to SO₂ poisoning were tested for a series of Pd/La-Cu-Co-O/cordierite catalysts, which were prepared using a multiple-step impregnation method. The XRD, SEM, and IR characterization techniques were performed to investigate the relationship between the catalytic performance and its physicochemical properties. When Pd/La-Cu-Co-O/cordierite catalysts with Pd loadings of 0.06 and 0.08 % were prepared at a calcination temperature of 500 °C for 5 h, they exhibited similar catalytic activity and sulfur resistance. When the concentration of benzene was 1500 ppm and the GHSV was 20000 h⁻¹, the benzene conversion was above 95 % at a reaction temperature of 350 °C in SO₂ existing at 100 ppm. These results were mainly attributed to the cooperation between La-Cu-Co-O perovskite and the noble metal Pd. Specifically, the addition of copper can strengthen the catalytic activity of La-Co-O/cordierite catalysts by decreasing the crystalline size of the active ingredients. A moderate Pd addition can drastically improve the sulfur resistance and further improve the catalytic activity of the La-Cu-Co-O/cordierite catalyst.
显示更多 [+] 显示较少 [-]An evaluation of hospital admission respiratory disease attributed to sulfur dioxide ambient concentration in Ahvaz from 2011 through 2013
2016
Goudarzi, Gholamreza | Geravandi, Sahar | Idani, Esmaeil | Hosseini, Seyyed Ahmad | Baneshi, Mohammad Mehdi | Yari, Ahmad Reza | Vosoughi, Mehdi | Dobaradaran, Sina | Shirali, Saeed | Marzooni, Mohammad Bagherian | Ghomeishi, Ali | Alavi, Nadali | Alavi, Seyedeh Shaghayegh | Mohammadi, Mohammad Javad
There is no doubt that air pollutants have adverse impacts on human health. The main objective of this study was to evaluate hospital admission respiratory disease (HARD) attributed to sulfur dioxide levels in Ahvaz during three successive years. Data was taken from Iranian Environmental Protection Agency (EPA). The AirQ2,2,3 model is used to quantify the impact of SO₂ on inhabitants of Ahvaz and in terms of hospital admission respiratory diseases. This is a kind of statistical model which is based on some epidemiological indices such as relative risk, baseline incidence, and attributable proportion. Sampling was already performed for 24 h in four stations during 2011–2013. Four stations are good representative for residential, high traffic, industry, and background sites which cover the whole area of the Ahvaz city. Regarding to gravimetric scale, raw data of sulfur dioxide was processed using Excel software. Encoding, filtering, and processing were conducted to prepare input file for the Air Q₂,₂,₃ model. After running model, outputs presented in term of hospital admissions respiratory cases. Based on our result, the highest mean and maximum of seasonal and annual levels for sulfur dioxide were observed in 2013. We concluded that obnoxious quality of fuel and some deficiencies in maintenance and operation of industries lead to worse quality of ambient air especially in 2013. Cumulative cases of HARD attributed to sulfur dioxide level at central of relative risk (RR) were estimated 24, 25, and 30 persons for 2011, 2012, and 2013, respectively. The finding of this study showed that total mean of sulfur dioxide was higher than standard concentration. We also noticed that wintertime concentrations of sulfur dioxide during three successive years were higher than of those levels in summer.
显示更多 [+] 显示较少 [-]No-tillage effects on N and P exports across a rice-planted watershed
2016
Liang, Xinqiang | Wang, Zhibo | Zhang, Yixiang | Zhu, Chunyan | Lin, Limin | Xu, Lixian
No tillage (NT) can be used as a management tool to alleviate the negative effects of agricultural practices on the environment by reducing the runoff volume and nutrient exports. The main objective of this research was to quantify the effect of NT on nitrogen (N) and phosphorus (P) exports across a rice-planted watershed using the soil and water assessment tool (SWAT) model. Results show that total N and P runoff exports from rice fields across the watershed ranged from 7.2 to 22.8 kg N/ha and 0.56 to 6.80 kg P/ha, respectively, over five rice-growing seasons under conventional tillage (CT) practice. The adoption of NT reduced the runoff volume, and the total N and total P exports by 25.9, 8.5, and 7.8 %, respectively, compared with the total exports under CT practice in the same study area. Rice yields were reduced by 0.7–1.9 % within the first 4 years after the adoption of NT, but began to rise in the fifth year. These results suggest that a long-term period of NT practice is necessary to reduce N and P exports without comprising the rice yield on rice-planted watersheds. In addition, the benefits of implementing NT practice alone were limited, and other practices, such as water and nutrient management, should be combined with NT practice.
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