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Moraru R Pourcher AM Jadas-Hecart A Kempf I Ziebal C Kervarrec M Comunal PY Mares M Dabert P 《Journal of environmental quality》2012,41(3):754-763
This study evaluated the impact of storing chicken manure on the degradation of enrofloxacin (ENR) and ciprofloxacin (CIP), and on the survival of CIP-resistant Enterobacteriaceae. At 24 d of age, half of 8900 chickens received ENR for 5 d. After the animals departed, their manure was stored in two heaps for 63 d. Enterobacteriaceae were cultured on media containing 0 to 32 mg L?1 of CIP. A total of 320 isolates were fingerprinted using enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) to evaluate community structure. Initial concentrations of ENR and CIP in the heap were 22 and 1.8 mg kg?1, respectively. Seventy-three percent of the two fluoroquinolones were eliminated during storage. The administration of ENR led to a 5.1 log??? decrease in Enterobacteriaceae concentrations and emergence of CIP-resistant bacteria, which became dominant in the feces. concentrations decreased 1.2 to 2.3 log??? 2 d after the heaps were made and continued to decline during storage. No resistant were found by Day 63. The highest CIP minimum inhibitory concentration (MIC) values observed among isolates of and of both and sp. were 128 and 4 mg L?1, respectively. The dominant ERIC-PCR profiles changed over time. There was no relationship between genotype and resistance-isolated strains to CIP. Storing chicken manure in heaps appeared to be an effective way of limiting the entrance of CIP-resistant E. coli into the environment but did not prevent the dissemination of fluoroquinolones after land spreading. 相似文献
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Simona Caprarescu Mihai Cosmin Corobe Violeta Purcar Catalin Ilie Spataru Raluca Ianchis Gabriel Vasilievici Zina Vuluga 《环境科学学报(英文版)》2015,35(9):27-37
Heterogeneous membranes were obtained by using styrene-acrylonitrile copolymer (SAN) blends with low content of ion-exchanger particles (5 wt.%). The membranes obtained by phase inversion were used for the removal of copper ions from synthetic wastewater solutions by electrodialytic separation. The electrodialysis was conducted in a three cell unit, without electrolyte recirculation. The process, under potentiostatic or galvanostatic control, was followed by pH and conductivity measurements in the solution. The electrodialytic performance, evaluated in terms of extraction removal degree (rd) of copper ions, was better under potentiostatic control then by the galvanostatic one and the highest (over 70%) was attained at 8 V. The membrane efficiency at small ion-exchanger load was explained by the migration of resin particles toward the pores surface during the phase inversion. The prepared membranes were characterized by various techniques i.e. optical microscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis and differential thermal analysis and contact angle measurements. 相似文献
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Ionela Birloaga Ida De Michelis Francesco Ferella Mihai Buzatu Francesco Vegliò 《Waste management (New York, N.Y.)》2013,33(4):935-941
The present lab-scale experimental study presents the process of leaching waste printed circuit boards (WPCBs) in order to recover gold by thioureation. Preliminary tests have shown that copper adversely affects gold extraction; therefore an oxidative leaching pre-treatment was performed in order to remove base metals. The effects of sulfuric acid concentration, hydrogen peroxide volume and temperature on the metal extraction yield were studied by analysis of variance (ANOVA). The highest copper extraction yields were 76.12% for sample A and 18.29% for sample D, after leaching with 2 M H2SO4, 20 ml of 30% H2O2 at 30 °C for 3 h. In order to improve Cu removal, a second leaching was performed only on sample A, resulting in a Cu extraction yield of 90%. Other experiments have shown the negative effect of the stirring rate on copper dissolution. The conditions used for the process of gold extraction by thiourea were: 20 g/L thiourea, 6 g/L ferric ion, 10 g/L sulfuric acid, 600 rpm stirring rate. To study the influence of temperature and particle size, this process was tested on pins manually removed from computer central processing units (CPUs) and on waste CPU for 3½ h. A gold extraction yield of 69% was obtained after 75% of Cu was removed by a double oxidative leaching treatment of WPCBs with particle sizes smaller than 2 mm. 相似文献
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Acrylonitrile-butadiene-styrene (ABS) copolymers without and with a polybrominated epoxy type flame retardant were thermally degraded at 450 degrees C alone (10 g) and mixed with polyvinylchloride (PVC) (8 g/2 g). Gaseous and liquid products of degradation were analysed by various gas chromatographic methods (GC with TCD, FID, AED, MSD) in order to determine the individual and cumulative effect of bromine and chlorine on the quality and quantity of degradation compounds. It was found that nitrogen, chlorine, bromine and oxygen are present as organic compounds in liquid products, their quantity depends on the pyrolysed polymer or polymer mixture. Bromophenol and dibromophenols were the main brominated compounds that come from the flame retardant. 1-Chloroethylbenzene was the main chlorine compound observed in liquid products. It was also determined that interactions appear at high temperatures during decomposition between the flame retardant, PVC and the ABS copolymer. 相似文献
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Chemical, biological, and ecotoxicological assessment of pesticides and persistent organic pollutants in the Bahlui River, Romania 总被引:1,自引:0,他引:1
Mariana Neamtu Ioan M. Ciumasu Naela Costica Mihai Costica Magda Bobu Mircea N. Nicoara Cezar Catrinescu Kristin Becker van Slooten Luiz F. De Alencastro 《Environmental science and pollution research international》2009,16(Z1):76-85
Background, aim, and scope
Current knowledge on environmental impacts of industrial activities in Romania, particularly persistent organic pollutants (POPs), indicates that environmental standards of the European Union are not systematically met. In our study area, additional sources of POPs are agriculture and domestic wastes. Very scarce information is available upon environmental contaminations and effects. In the present study, we investigated the chemical pollution and their eventual impact on the ecosystem by measuring POPs and by using biological indicators of pollution. 相似文献7.
Mineral resources represent an integral component within a country’s economy. Despite the fact that the need for raw materials undergoes continuous growth–especially in countries which experience industrial upswing–proper measures to secure the access to domestic mineral resources in the long term have only been applied marginally in a large number of states. This lack of future-oriented legal frameworks–referred to as ‘Minerals Policies’–might lead to a diversity of sectoral problems (eg. dependency on certain raw materials imports). Based on data analysis and subsequent demand forecasting comprehensive national Minerals Policies can be derived in order to anticipate emerging issues and to achieve optimum sustainable management of domestic geological resources. The necessity of such concepts is illustrated by the example of Romania focusing on non-energetic mineral resources. 相似文献
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Catalina Munteanu Cornelius Senf Mihai D. Nita Francesco Maria Sabatini Julian Oeser Rupert Seidl Tobias Kuemmerle 《Conservation biology》2022,36(2):e13820
High-conservation-value forests (HCVFs) are critically important for biodiversity and ecosystem service provisioning, but they face many threats. Where systematic HCVF inventories are missing, such as in parts of Eastern Europe, these forests remain largely unacknowledged and therefore often unprotected. We devised a novel, transferable approach for detecting HCVFs based on integrating historical spy satellite images, contemporary remote sensing data (Landsat), and information on current potential anthropogenic pressures (e.g., road infrastructure, population density, demand for fire wood, terrain). We applied the method to the Romanian Carpathians, for which we mapped forest continuity (1955–2019), canopy structural complexity, and anthropogenic pressures. We identified 738,000 ha of HCVF. More than half of this area was identified as susceptible to current anthropogenic pressures and lacked formal protection. By providing a framework for broad-scale HCVF monitoring, our approach facilitates integration of HCVF into forest conservation and management. This is urgently needed to achieve the goals of the European Union's Biodiversity Strategy to maintain valuable forest ecosystems. 相似文献
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Anicuta Stoica-Guzun Luiza Jecu Amalia Gheorghe Iuliana Raut Marta Stroescu Marius Ghiurea Mihai Danila Iuliana Jipa Victor Fruth 《Journal of Polymers and the Environment》2011,19(1):69-79
The ability of fungal strains to attack a composite material obtained from poly(vinyl alcohol) (PVA) and bacterial cellulose
(BC) is investigated. The fungal strain tested was Aspergillus niger. This fungal strain was able to change not only the polymer surface from smoother to rougher, but also to disrupt the polymer.
The degradation results were confirmed by visual observations, scanning electron microscopy (SEM) analyses, X-ray diffraction
analyses and FTIR spectra of the film samples. SEM micrographs confirmed the growth of fungi on the composite film surface.
The degree of microbial degradation depends on culture medium and on composition of polymeric materials, especially on PVA
content. The biodegradation process is accelerated by the presence of glucose in the culture medium as an easily available
carbon source. 相似文献