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Resultados 1331-1340 de 3,243
Strategies for the Decoupling Effect of Carbon Emission and Low Carbon in the Logistics Industry of Jiangxi Province: From the Perspective of Environmental Protection
2015
Zhang Zhijian | Zhang Cheng | Feng Yaping | Wu Ningyuan
Being one of the main sources of carbon emissions, logistics industry is an important area to reduce greenhouse gas emissions and the environment pollution. Studying the decouple relation between carbon emission and economic growth can provide a theoretical basis for energy conservation and low carbon economy development. The LYQ analysis framework was introduced into the OECD and Tapio decoupling model to measure the decoupling effect between the carbon emission in logistics industry and the economic growth of Jiangxi Province China during the past 25 years (1989-2013). In the LYQ analysis framework, the decoupling elastic coefficient between the carbon emission in logistics industry and the regional GDP was converted into the products of the elastic coefficients of energy conservation, emission reduction, and value creation. The result shows that the relationship between the carbon emission and economic growth of Jiangxi Province is involved in overall decoupling status, in which the positive effects of the elastic coefficient of energy conversation and the elastic coefficient of emission reduction are the main factors, and the low elasticity coefficient of value creation at the early period becomes an obstacle to the decoupling status. What is more, several low carbon development strategies are put forward in the logistics industry from the perspective of environmental protection. This study has great theoretical and practical significance for the development of low-carbon economy in Jiangxi Province, China.
Mostrar más [+] Menos [-]Concentrations of 18 Elements in Muscle, Liver, Gills, and Gonads of Sichel (Pelecus cultratus), Ruffe (Gymnocephalus cernua), and European Perch (Perca fluviatilis) in the Danube River near Belgrade (Serbia)
2015
Subotić, S. | Višnjić-Jeftić, Ž | Spasić, S. | Hegediš, A. | Krpo-Ćetković, J. | Lenhardt, M.
The analysis of 18 elements in muscle, liver, gills, and gonads of sichel (Pelecus cultratus), ruffe (Gymnocephalus cernua), and European perch (Perca fluviatilis), caught at a polluted segment of the Danube River near Belgrade, was carried out with the aim to expand the knowledge about the ecotoxicology of these species for monitoring purposes and the possible impact on human health. Generally, the elemental concentration significantly differed between species and tissues (p < 0.0001), and a statistical interaction between these two factors was observed (p < 0.0001). In muscle and liver, concentrations of Hg and Se were statistically higher in ruffe than in sichel and European perch. In gills, statistically highest concentrations of Mn, Sr, and Zn were found in sichel, and of Fe in European perch. In gonads, statistically highest concentrations of As were detected in sichel, of Zn in ruffe, and of Mn and Mo in European perch. The highest number of coefficients of partial correlations between fish weight and element levels was found in sichel (11 in total). Of all analyzed elements, Al and B had the highest number of partial correlations in tissues. The levels of Hg exceeded the maximum acceptable concentration (0.5 mg kg⁻¹) in all muscle samples, which can pose a risk for human consumption. Different diet preferences of the investigated fish species resulted in a different accumulation of elements in tissues, and ruffe (as a species that consume mainly benthic macroinvertebrates) accumulated the highest level of Hg, which makes it suitable for monitoring of this element in water bodies.
Mostrar más [+] Menos [-]Pathogen Inactivation and the Chemical Removal of Phosphorus from Swine Wastewater
2015
Viancelli, A. | Kunz, A. | Fongaro, G. | Kich, J. D. | Barardi, C. R. M. | Suzin, L.
Inactivation of pathogens present in animal manure prior to land application has justified the use of advanced technologies. However, some alternatives are expensive or not effective due to the organic material and suspended solids present in the effluent (e.g., ozone, UV light). The use of hydrated lime (calcium hydroxide, Ca(OH)₂) is an attractive wastewater treatment option due to the ability of lime to kill pathogens and to extract phosphorus from manure at an alkaline pH. The present study aimed to evaluate the soluble phosphorus removal and pathogen inactivation (Escherichia coli, Salmonella enterica serovar typhymurium and Porcine circovirus type 2), in the liquid fraction and in the solid generated after Ca(OH)₂ addition in swine wastewater, exposed for 3 and 24 h at different pH conditions: 9.0, 9.5, and 10.0. The results showed the efficiency of pH elevation with Ca(OH)₂ in the removal of soluble P at pH 9.0 and the total inactivation of E. coli, Salmonella, and P. circovirus type 2 at pH 10.0. The liquid fraction (reuse water) could be safely used for cleaning the swine production facilities, and the solid fraction (precipitated P) could be used as a secondary product and fertilizer.
Mostrar más [+] Menos [-]The Increase in Bismuth Consumption as Reflected in Sewage Sludge
2015
Amneklev, Jennie | Sörme, Louise | Augustsson, Anna | Bergbäck, Bo
As the use of dangerous substances in consumer products increases, these substances may also be found in society’s end products, among them sewage sludge. Measuring concentrations in sewage sludge can be a way to reflect the consumption of a substance. By using substance flow analysis, the inflow, stock and outflow of the specific substance to, e.g. a city region, may be analysed. Bismuth is a heavy metal that is found in increasing levels in sewage sludge in Swedish wastewater treatment plants (WWTPs) and a similar increase cannot be excluded for WWTPs around the world. This study aims to examine possible sources that could explain the amounts measured in one Swedish WWTP. Household products such as cosmetics (24 %) and plastics (14 %) are found to be major sources of Bi measured in sewage sludge. The remaining unidentified amounts in this study (approximately 50 %) are most likely found in effluent waters from industries or sources outside the household. There is, however, no information on measurements of Bi released by industry available and there is no legislation in place that may encourage industry to conduct such measurements.
Mostrar más [+] Menos [-]Phytoremediation Ability of Solanum nigrum L. to Cd-Contaminated Soils with High Levels of Cu, Zn, and Pb
2015
Yu, Cailian | Peng, Xianlong | Yan, Hong | Li, Xiaoxia | Zhou, Zhenhua | Yan, Tingliang
Solanum nigrum L., a potential cadmium (Cd) hyper-accumulator, has not currently been investigated to identify if it has a strong simultaneous accumulative ability to Cd, copper (Cu), zinc (Zn), or lead (Pb) in contaminated soils. In this study, a pot culture experiment was conducted to investigate the phytoremediation effects of S. nigrum L. on these heavy metals. The potential hyper-accumulative characteristics of S. nigrum L. were also discussed. The results showed that S. nigrum L. remediation effects were not inhibited by multi-heavy metals in contaminated soil. On the contrary, the height and wet and dry weights of S. nigrum L. increased compared to the control treatments and to treatments using only one heavy metal contaminant. Results from the Cd treatment experiments showed 1.66- and 1.45-fold increases in stem and root levels; there were also 1.24-, 2.17-, and 1.61-fold extraction increases in the leaves, stems, and roots, respectively. The differences found in shoot and root bioaccumulation coefficient (BC) factors for multi-heavy metal (MHM) treatment were higher than for a single Cd treatment. These results indicate that S. nigrum L. could stimulate biomass production and that it has a strong ability to tolerate and accumulate Cd in contaminated soils with Pb, Zn, and Cu. This study shows that the remediation scope for S. nigrum L. is greater than currently believed and that it will also remove Pb, Zn, and Cu while extracting Cd from contaminated soils.
Mostrar más [+] Menos [-]Contribution of Coagulation–Flocculation Process for a More Sustainable Pig Slurry Management
2015
Fragoso, R. A. | Duarte, E. A. | Paiva, J.
This paper aims to demonstrate the benefits of using a natural coagulant to enhance gravitational sedimentation of pig slurry. The separation process would lead to a liquid fraction, more biodegradable and with lower nutrient content, and a solid fraction highly concentrated in organic matter. Experimental trials were conducted in order to achieve the following objectives: (i) compare the effect of gravitational sedimentation with coagulation–flocculation process, (ii) compare the efficiency of conventional coagulants (such as aluminium sulphate or ferric chloride) with chitosan biopolymer and (iii) test the optimum coagulation–flocculation operational conditions to slurry sample. Assessment criteria included removal efficiencies but also took into consideration the advantages/disadvantages regarding sludge management. Results showed that gravitational sedimentation process can be improved by addition of coagulants; turbidity and COD removal increased around 2 and 3 times, respectively.
Mostrar más [+] Menos [-]Nitric Oxide Attenuates Oxidative Stress Induced by Arsenic in Lettuce (Lactuca sativa) Leaves
2015
Silveira, Neidiquele M. | de Oliveira, Juraci A. | Ribeiro, Cleberson | Canatto, Regiane A. | Siman, Luhan | Cambraia, José | Farnese, Fernanda
Lettuce plants were exposed to different toxic levels of arsenic (As) to induce an oxidative stress response, and the role of nitric oxide (NO) (provided as sodium nitroprusside (SNP)) as an attenuating agent of this stress condition was evaluated. Plants were treated with 50 μM of As with or without 100 μM SNP added to the nutrient solution. The hydrogen peroxide, superoxide anion, and malondialdehyde concentrations and enzymatic activities were measured. The increase in As concentration detected in the leaves was followed by a significant increase in H₂O₂ and malondialdehyde (MDA) concentrations. However, the presence of SPN promoted a reduction in the concentration of these oxidative agents and also reduced the translocation of As to the shoots. The enzymatic activities in the plants exposed to As were increased, which indicates the active participation of these enzymes in the reduction of oxidative stress induced by the metalloid. In the plants exposed to As and SNP, the enzymatic activities were not so high; this result was possibly related to the direct action of NO in scavenging the generated toxic metabolites and with the reduction in the translocation of the pollutant to the shoots. Lettuce and leaves of other vegetables are usually ingested, and this study shows an alternative to avoid human contamination with As.
Mostrar más [+] Menos [-]Arsenic Adsorption Using Palm Oil Waste Clinker Sand Biotechnology: an Experimental and Optimization Approach
2015
Rehman, Muhammad Abdur | Ismail Yusoff, | Ahmmad, Rasel | Alias, Yatimah
We need specific and competent adsorbents to remove arsenic and bring it down to permissible levels in drinking water. Therefore, industrial byproducts are extensively applied to produce large amounts of natural adsorbents. Similarly, managing optimum arsenic adsorption with palm oil clinker sand (POCS) is possible through a careful statistical planning of adsorption variables. We plan and perform a minimum number of experiments to (1) obtain optimum arsenic adsorption and (2) provide a new possible application opportunity to the industrial waste managers and future planners. We observed that adsorption of arsenic was dependent on the pH of the system, initial concentration of arsenic (mg L⁻¹), amount (mg) of POCS, and temperature of the bio-adsorption system. A correlation among the study variables was constructed by three-dimensional (3D) response surfaces and two-dimensional (2D) contour plots based on central composite design (CCD) experiments in a batch mode of study. A quadratic model fitted well with the experimental data and better explained the superiority of current bio-adsorption system and efficient removal of arsenic from water samples. We confirmed that the selected variables were experimentally and statistically significant and controlled the overall adsorption response by the batch system. A comparative and thorough analysis of the adsorption process confirmed that selected variables were mutually interacting in a nonlinear fashion in this study. Excellent experimental results and external comparative studies prove the relative importance of the present model and adsorption system for arsenic remediation biotechnology.
Mostrar más [+] Menos [-]Chemometric Analysis for Pollution Source Assessment of Harbour Sediments in Arctic Locations
2015
Pedersen, Kristine B. | Lejon, Tore | Jensen, Pernille E. | Ottosen, Lisbeth M.
Pollution levels, pollutant distribution and potential source assessments based on multivariate analysis (chemometrics) were made for harbour sediments from two Arctic locations; Hammerfest in Norway and Sisimiut in Greenland. High levels of heavy metals were detected in addition to organic pollutants. Preliminary assessments based on principal component analysis (PCA) revealed different sources and pollutant distribution in the sediments of the two harbours. Tributyltin (TBT) was, however, found to originate from point source(s), and the highest concentrations of TBT in both harbours were found adjacent to the former shipyards. Polyaromatic hydrocarbons (PAH) ratios and PCA plots revealed that the predominant source in both harbours was pyrogenic related to coal/biomass combustion. Comparison of commercial polychlorinated biphenyls (PCB) mixtures with PCB compositions in the sediments indicated relation primarily to German, Russian and American mixtures in Hammerfest; and American, Russian and Japanese mixtures in Sisimiut. PCA was shown to be an important tool for identifying pollutant sources and differences in pollutant composition in relation to sediment characteristics.
Mostrar más [+] Menos [-]Solvent Tolerance Mechanisms in Shewanella putrefaciens IBBPo6
2015
Stancu, Mihaela Marilena
Shewanella putrefaciens IBBPₒ₆(KM405339) showed good tolerance to 5 % organic solvents. The growth was higher when S. putrefaciens IBBPₒ₆cells were exposed to n-decane, as compared with the growth of cells exposed to toluene, o-xylene, ethylbenzene, cyclohexane, or n-hexane. Thus, n-decane was less toxic for S. putrefaciens IBBPₒ₆cells, while toluene, o-xylene, ethylbenzene, cyclohexane, and n-hexane were more toxic for this bacterium. The release of nucleic acids was higher when S. putrefaciens IBBPₒ₆cells were exposed to toluene, o-xylene, ethylbenzene, cyclohexane, or n-hexane, as compared with the release of nucleic acids from control cells and n-decane exposed cells. The cell surface hydrophobicity increased when S. putrefaciens IBBPₒ₆cells were exposed to n-decane, while in the presence of toluene, o-xylene, ethylbenzene, cyclohexane, and n-hexane, a decrease in the cell surface hydrophobicity was acquired. The exposure of S. putrefaciens IBBPₒ₆cells to 5 % organic solvents had induced biofilms formation, and their structure differs according to the nature of the hydrophobic substrate. Two secondary metabolites (i.e., biosurfactants, carotenoids) were produced by S. putrefaciens IBBPₒ₆control cells, as well as by the cells exposed to 5 % organic solvents. S. putrefaciens IBBPₒ₆possesses alkB1 and alkM1 catabolic genes and HAE1 transporter gene. A homologue of otsA1 gene was also detected in this bacterium. Some differences between the polymerase chain reaction (PCR) patterns of S. putrefaciens IBBPₒ₆control cells and cells exposed to 5 % organic solvents were observed. Distinct repetitive sequence-based PCR (rep-PCR), random amplification of DNA fragments (RAPD), and amplified ribosomal DNA restriction analysis (ARDRA) patterns were also acquired in S. putrefaciens IBBPₒ₆cells exposed to 5 % organic solvents, compared with the control cells.
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