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Resultados 1141-1150 de 4,042
Sustainability and the Spanish port system. Analysis of the relationship between economic and environmental indicators Texto completo
2016
Laxe, Fernando González | Bermúdez, Federico Martín | Palmero, Federico Martín | Novo Corti, Isabel
Research into the methodological development of alternative systems of sustainability measures is recent. In understanding sustainable development in a multi-dimensional sense, one of the most significant advances was the construction of Synthetic Indexes, applicable to different spatial spheres or to organisations, businesses, institutions, etc.The Spanish port system of general interest comprises 46 ports integrated in 28 Port Authorities, which in 2014 moved 482,000,000t of goods and more than 28 million passengers. This gives an idea of its importance for the Spanish economy.Using a derivation of the procedure used to calculate the Port Sustainability Synthetic Index, in this research the analysis of the relationship that exists between the findings obtained for the economic and environmental dimensions is used. This enables the existence of links between ports and economic and environmental indicators for a sample of 16 Port Authorities of Spain to be verified.
Mostrar más [+] Menos [-]Bioremediation technologies for polluted seawater sampled after an oil-spill in Taranto Gulf (Italy): A comparison of biostimulation, bioaugmentation and use of a washing agent in microcosm studies Texto completo
2016
Crisafi, F. | Genovese, M. | Smedile, F. | Russo, D. | Catalfamo, M. | Yakimov, M. | Giuliano, L. | Denaro, R.
One of the main challenges of bioremediation is to define efficient protocols having a low environmental impact. We have investigated the effect of three treatments in oily-seawater after a real oil-spill occurred in the Gulf of Taranto (Italy). Biostimulation with inorganic nutrients allowed the biodegradation of the 73±2.4% of hydrocarbons, bioaugmentation with a selected hydrocarbonoclastic consortium consisting of Alcanivorax borkumensis, Alcanivorax dieselolei, Marinobacter hydrocarbonoclasticus, Cycloclasticus sp. 78-ME and Thalassolituus oleivorans degraded 79±3.2%, while the addition of nutrients and a washing agent has allowed the degradation of the 69±2.6%. On the other hand, microbial community was severely affected by the addition of the washing agent and the same product seemed to inhibit the growth of the majority of strains composing the selected consortium at the tested concentration. The use of dispersant should be accurately evaluated also considering its effect on the principal actors of biodegradation.
Mostrar más [+] Menos [-]Combined environmental stress from shrimp farm and dredging releases in a subtropical coastal lagoon (SE Gulf of California) Texto completo
2016
Cardoso-Mohedano, J.G. | Páez-Osuna, F. | Amezcua-Martínez, F. | Ruiz-Fernández, A.C. | Ramírez-Reséndiz, G. | Sanchez-Cabeza, J.A.
Nutrient pollution causes environmental damages on aquatic ecosystems worldwide. Eutrophication produces impacts in coastal ecosystems, affecting biota and ecosystem services. The Urias coastal lagoon (SE Gulf of California) is a sub-tropical estuary under several environmental pressures such as nutrient inputs from shrimp farm effluents and dredging related to port operations, which can release substances accumulated in sediments. We assessed the water quality impacts caused by these activities and results showed that i) nitrogen was the limiting nutrient, ii) shrimp farm effluents increased particulate organic matter and chlorophyll a in the receiving stations, and iii) dredging activities increased nitrite and reduced dissolved oxygen concentrations. The co-occurrence of the shrimp farm releases and dredging activities was likely the cause of a negative synergistic effect on water quality which mainly decreases dissolved oxygen and increases nitrite concentrations. Coastal zone management should avoid the co-occurrence of these, and likely others, stressors in coastal ecosystems.
Mostrar más [+] Menos [-]Contamination and distribution of heavy metals, polybrominated diphenyl ethers and alternative halogenated flame retardants in a pristine mangrove Texto completo
2016
Wu, Qihang | Leung, Jonathan Y.S. | Tam, Nora F.Y. | Peng, Yisheng | Guo, Pengran | Zhou, Song | Li, Qing | Geng, Xinhua | Miao, Shenyu
Contamination and distribution of heavy metals, polybrominated diphenyl ethers and alternative halogenated flame retardants in a pristine mangrove Texto completo
2016
Wu, Qihang | Leung, Jonathan Y.S. | Tam, Nora F.Y. | Peng, Yisheng | Guo, Pengran | Zhou, Song | Li, Qing | Geng, Xinhua | Miao, Shenyu
Owing to the expanding metal and electronics industries, pollution in the Pearl River Estuary needs special concern. Given the hydrodynamic effect, the pristine mangrove in Qi'ao Island would be contaminated by tidal flushing. Thus, we examined (1) the contamination of pollutants in this mangrove, including heavy metals, polybrominated diphenyl ethers (PBDEs) and alternative halogenated flame retardants (AHFRs), and (2) how habitat characteristics and sediment properties affect their distribution. Results showed that the sediment in Qi'ao mangrove had higher concentrations of heavy metals, PBDEs and AHFRs than that in other pristine mangroves, and similar concentrations to those mangroves impacted by point sources. Heavy metal concentrations were lower in the vegetated areas than mudflat, while the opposite was found for PBDEs and AHFRs. The findings imply that tidal flushing was an important pollution source, while mangrove plants have the capacity to minimize the impact of heavy metals, but not PBDEs and AHFRs.
Mostrar más [+] Menos [-]Contamination and distribution of heavy metals, polybrominated diphenyl ethers and alternative halogenated flame retardants in a pristine mangrove Texto completo
2016
Wu, Q. | Leung, J. | Tam, N. | Peng, Y. | Guo, P. | Zhou, S. | Li, Q. | Geng, X. | Miao, S.
Abstract not available | Qihang Wu, Jonathan Y.S. Leung, Nora F.Y. Tam, Yisheng Peng, Pengran Guo, Song Zhou, Qing Li, Xinhua Geng, Shenyu Miao
Mostrar más [+] Menos [-]Characteristics and sources of PM in seasonal perspective – A case study from one year continuously sampling in Beijing Texto completo
2016
Shen, Rongrong | Schäfer, Klaus | Schnelle-Kreis, Jürgen | Shao, Longyi | Norra, Stefan | Kramar, Utz | Michalke, Bernhard | Abbaszade, Gülcin | Streibel, Thorsten | Fricker, Mathieu | Chen, Yuan | Zimmermann, Ralf | Emeis, Stefan | Schmid, Hans-Peter
Daily mass concentrations and chemical compositions (elemental carbon, organic carbon, water soluble ions, chemical elements and organic species) of PM were measured continuously in Beijing for one year from June 2010 to June 2011 (365 samples). The seasonal variation of PM mass concentration followed the order of spring 2011 > winter 2010 > summer 2010 > autumn 2010. Organic matter (OM) and secondary inorganic aerosol components (SNA: SO42−, NO3− and NH4+) were the two major fractions of PM during the whole year. Source apportionment by PMF performed on the basis of a full year of data, including both inorganic and organic species, showed that biomass burning, secondary sulfate and nitrate formation, mineral dust, industry, coal combustion and traffic were the main sources of PM in Beijing during 2010–2011. Specifically, comparison among the four seasons shows that the contribution of secondary sulfate and biomass burning, secondary nitrate formation, mineral dust, and coal combustion were the dominating sources of PM in summer, autumn, spring and winter, respectively. The contributions of industry to PM was distributed evenly in four seasons, while traffic contributed more in summer and autumn than in winter and spring. Backward trajectory analysis was applied in combination with PMF and showed that air flow from the South contributed mostly to high PM mass concentrations in Beijing. Meteorological parameters (temperature, wind speed, wind direction, precipitation and mixing layer height) influence such a variation. In general, high relative humidity and low mixing layer height can raise PM mass concentration, while high wind speed and precipitation can reduce pollutants. In addition, wind direction also plays a key role in influencing PM because different wind directions can bring different pollutants to Beijing from different regions.
Mostrar más [+] Menos [-]Spatial variation and provenance of atmospheric trace elemental deposition in Beijing Texto completo
2016
Zheng, Xiaoxia | Guo, Xiaoyu | Zhao, Wenji | Shu, Tongtong | Xin, Yanan | Yan, Xing | Xiong, Qiulin | Chen, Fantao | Lv, Ming
Atmospheric dry deposition samples were collected in urban and suburban areas of Beijing during a coal-burning period. Chemical characteristics of lanthanoid elements (La–Lu) and five heavy metals (Cr, Co, Mo, Cd, and Pb) were analyzed to determine the variation in spatial scale and deposition provenances. Factor analysis and ternary diagrams were used to identify principle pollution sources. The LaCeSm ternary diagram was used to identify oil refineries using fluid catalytic converters and steel plants, but could not differentiate crustal materials. Lanthanoid characteristic parameters showed similarity between deposition and soil in the local and southwest area in the vicinity of Beijing. Analysis of the five heavy metals enabled discrimination of contaminants originating from human activities. Cd, Pb, and Mo were found to originate from vehicular traffic, whereas Co and Cr originated from industrial emissions and coal combustion. Discriminant analysis established the causes of spatial variation. The result shows that Co, Mo, and Pb can mark the differences between urban and suburban sites. From the PbMoCo plot, it was inferred that the different chemical characters are mainly due to the differing origins of depositions. Deposition samples in suburban areas are principally influenced by soil, chimney soot, and fertilizer, whereas those in urban area are mainly affected by traffic emissions.
Mostrar más [+] Menos [-]Optimisation for assay of fluorescein diacetate hydrolytic activity as a sensitive tool to evaluate impacts of pollutants and nutrients on microbial activity in coastal sediments Texto completo
2016
Jiang, Shan | Huang, Jing | Lu, Haoliang | Liu, Jingchun | Yan, Chongling
Fluorescein diacetate (FDA) assay has been widely applied in coastal research to quantify microbial activity in sediments. However, the present FDA assay procedures embodied in sediment studies potentially include operational errors since the protocol was established for studies of terrestrial soil. In the present study, we optimised the procedure of FDA assay using sandy and cohesive sediments to improve experiential sensitivity and reproducibility. The optimised method describes quantitative measurement of the fluorescein produced when 1.0g of fresh sediment is incubated with 50mM phosphate buffer solution (pH: 7.3) and glass beads (2g) at 35°C for 1h under a rotation of 50rpm. The covariation coefficient of the optimised method ranged from 1.9% to 3.8% and the method sensitivity ranged from 0.25 to 1.57. The improved protocol provides a more reliable measurement of the FDA hydrolysis rate over a wide range of sediments compared to the original method.
Mostrar más [+] Menos [-]Bacterial inoculants for enhanced seed germination of Spartina densiflora: Implications for restoration of metal polluted areas Texto completo
2016
Paredes-Páliz, Karina I. | Pajuelo, Eloísa | Doukkali, Bouchra | Caviedes, Miguel Ángel | Rodríguez-Llorente, Ignacio D. | Mateos-Naranjo, Enrique
The design of effective phytoremediation programs is severely hindered by poor seed germination on metal polluted soils. The possibility that inoculation with plant growth promoting rhizobacteria (PGPR) could help overcoming this problem is hypothesized. Our aim was investigating the role of PGPR in Spartina densiflora seed germination on sediments with different physicochemical characteristics and metal pollution degrees. Gram negative Pantoea agglomerans RSO6 and RSO7, and gram positive Bacillus aryabhattai RSO25, together with the consortium of the three strains, were used for independent inoculation experiments. The presence of metals (As, Cu, Pb and Zn) in sediments reduced seed germination by 80%. Inoculation with Bacillus aryabhattai RSO25 or Pantoea agglomerans RSO6 and RSO7 enhanced up to 2.5 fold the germination rate of S. densiflora in polluted sediments regarding non-inoculated controls. Moreover, the germination process was accelerated and the germination period was extended. The consortium did not achieve further improvements in seed germination.
Mostrar más [+] Menos [-]Effect of nutrient enrichment on the source and composition of sediment organic carbon in tropical seagrass beds in the South China Sea Texto completo
2016
Liu, Songlin | Jiang, Zhijian | Zhang, Jingping | Wu, Yunchao | Lian, Zhonglian | Huang, Xiaoping
To assess the effect of nutrient enrichment on the source and composition of sediment organic carbon (SOC) beneath Thalassia hemprichii and Enhalus acoroides in tropical seagrass beds, Xincun Bay, South China Sea, intertidal sediment, primary producers, and seawater samples were collected. No significant differences on sediment δ13C, SOC, and microbial biomass carbon (MBC) were observed between T. hemprichii and E. acoroides. SOC was mainly of autochthonous origin, while the contribution of seagrass to SOC was less than that of suspended particulate organic matter, macroalgae and epiphytes. High nutrient concentrations contributed substantially to SOC of seagrass, macroalgae, and epiphytes. The SOC, MBC, and MBC/SOC ratio in the nearest transect to fish farming were the highest. This suggested a more labile composition of SOC and shorter turnover times in higher nutrient regions. Therefore, the research indicates that nutrient enrichment could enhance plant-derived contributions to SOC and microbial use efficiency.
Mostrar más [+] Menos [-]Tracking pollutant characteristics during haze events at background site Zhongmu, Henan Province, China Texto completo
2016
Yu, Fei | Yan, Qishe | Jiang, Nan | Su, Fangcheng | Zhang, Leishi | Yin, Shasha | Li, Yang | Zhang, Ruiqin | Chen, Liangfu
Recently, China has faced a large scale air pollution problem not only in urban but also in rural areas. To better understand the occurrence of haze events and properties of particulate matter (PM) in rural area, continuous monitoring of PM and its related characteristics is necessary. Consequently, in this study, a comprehensive observation was performed at a rural site of Zhongmu, Henan Province. The meteorological parameters, physical and chemical properties including number and mass concentration, size resolved and water soluble ions were measured. During the observation period, the highest hourly mass concentration of PM2.5 obtained from Electrical Low Pressure Impactor plus (ELPI+) was 560 μg/m3 on January 5, 2015. The Hybrid Single-Particle Lagrangian Integrated Trajectory model shows that the most polluted day (January 5) was under the influence of static stability meteorological conditions and greatly influenced by the surrounding regional (within 200 km). During new particle formation stage, higher number concentration in nucleation mode (<30 nm) was found. Through the measurement of water-soluble inorganic ions, it was found that Ca2+ was the highest water-soluble inorganic ions in the coarse fraction (PM2.1–10) while SO42−, NO3− and NH4+ were the three major species in the fine fraction (PM2.1). Furthermore, the ratio of [NH4+]/(2[SO42−] + [NO3−]) was higher in fine particulate and [NH4+]/[SO42−] was more than 2 in fine particulate, indicating the presence of both (NH4)2SO4 and NH4NO3 in fine particulate during haze days. The regional transport and to some extent local dust were responsible for haze formation in the observed site.
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