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11.
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
12.
Andrew J. McElrone Jason G. Hamilton Mihai Aldea Evan H. DeLucia 《Environmental pollution (Barking, Essex : 1987)》2010,158(1):108-114
Atmospheric CO2 concentrations are predicted to double within the next century and alter climate regimes, yet the extent that these changes will affect plant diseases remains unclear. In this study conducted over five years, we assessed how elevated CO2 and interannual climatic variability affect Cercospora leaf spot diseases of two deciduous trees. Climatic data varied considerably between the five years and altered disease expression. Disease incidence and severity for both species were greater in years with above average rainfall. In years with above average temperatures, disease incidence for Liquidambar styraciflua was decreased significantly. When significant changes did occur, disease incidence and severity always increased under elevated CO2. Chlorophyll fluorescence imaging of leaves revealed that any visible increase in disease severity induced by elevated CO2 was mitigated by higher photosynthetic efficiency in the remaining undamaged leaf tissue and in a halo surrounding lesions. 相似文献
13.
Traian Buzatu Gabriela Popescu Ionela Birloaga Simona Săceanu 《Waste management (New York, N.Y.)》2013,33(3):699-705
Used batteries contain numerous metals in high concentrations and if not disposed of with proper care, they can negatively affect our environment. These metals represent 83% of all spent batteries and therefore it is important to recover metals such as Zn and Mn, and reuse them for the production of new batteries. The recovery of Zn and Mn from used batteries, in particular from Zn–C and alkaline ones has been researched using hydrometallurgical methods. After comminution and classification of elemental components, the electrode paste resulting from these processes was treated by chemical leaching. Prior to the leaching process the electrode paste has been subjected to two washing steps, in order to remove the potassium, which is an inconvenient element in this type of processes. To simultaneously extract Zn and Mn from this paste, the leaching method in alkaline medium (NaOH solution) and acid medium (sulphuric acid solution) was used. Also, to determine the efficiency of extraction of Zn and Mn from used batteries, the following variables were studied: reagents concentration, S/L ratio, temperature, time. The best results for extraction yield of Zn and Mn were obtained under acid leaching conditions (2 M H2SO4, 1 h, 80 °C). 相似文献
14.
Cornelia Vasile Mihai Brebu Hristea Darie Georgeta Cazacu 《Journal of Material Cycles and Waste Management》2010,12(2):147-153
Pyrolysis of polymer mixtures with a composition similar to that of municipal plastic waste containing polyvinyl chloride
(PVC) and of municipal plastic waste free of PVC was performed in the presence of components of biomass, namely lignin, cellulose,
or both. The pyrolysis products were characterized by standard methods utilized in the petrochemical industry, i.e., paraffins-isoparaffinsolefins-naphthenes-aromatics
analysis, proton nuclear magnetic resonance and infrared spectroscopy, and gas chromatography-mass spectrometry. Up to 3 wt%
lignin, cellulose, or both in mixed polymers changed the material balance of pyrolysis by decreasing the amount of waxy products.
The presence of both PVC and biomass components significantly changed the material balance by decreasing the waxy product
yield and increasing the gas and coke yield. The composition of all pyrolysis products was also modified with the addition
of PVC, components of biomass, or both. 相似文献
15.
Nona Merry M. Mitan Mihai Brebu Thallada Bhaskar Akinori Muto Yusaku Sakata Mitsuo Kaji 《Journal of Material Cycles and Waste Management》2007,9(1):62-68
Waste DVDs and CDs were thermally degraded at 450°C by a semibatch process. In total, 40–50 wt% was converted into liquid
product that consisted of phenol derivatives (∼75 wt%), bisphenol (∼10 wt%) and its derivatives, and small amounts of aromatic
hydrocarbons such as benzene, toluene, ethylbenzene, dimethylbenzene, methylethylbenzene, diethylbenzene, and methylisopropyl
benzene. Degradation of the polycarbonate support from DVDs and CDs was enhanced by coprocessing with vegetable cooking oil,
the degradation of which gave a homologue series of hydrocarbons and organic acids with up to 25 and 18 atoms of carbon, respectively.
Silver from the reflective coating on DVDs and CDs remained in the solid residue, its concentration increasing about 2.5 times
compared to that of the original disks. 相似文献
16.
Nona Merry M. Mitan Mihai Brebu Thallada Bhaskar Akinori Muto Yusaku Sakata 《Journal of Material Cycles and Waste Management》2007,9(1):56-61
Brominated high-impact polystyrene (HIPS-Br), which contained decabromodiphenyl ether flame retardant, and brominated acrylonitrile
butadiene styrene (ABS-Br), which contained bromine-containing epoxy-type flame retardant, were degraded at 450°C individually
and in a 1/1 mixture by a thermal and catalytic procedure using folded sheet mesoporous (FSM) and ZSM-5 zeolite in liquid
phase contact mode. The two polymers produced similar degradation oils but at a higher yield for HIPS-Br. However, the composition
and distribution of Br-, N-, and O-containing compounds depended on the type of flame retardant in HIPS-Br and ABS-Br. Multiphase
catalytic systems consisting of FSM in liquid phase contact mode and various CaH-, FeO-, CoMo-, and NiMo-based catalysts,
or combinations of these catalysts, in vapor phase contact mode were used to decrease the amount of heteroatoms (Br, N, and
O) in the degradation oils. Each system gave particular results in terms of mass balance and concentrations of heteroatoms.
A FSM (liquid phase contact)/CaHC (vapor phase contact) combination was the best catalytic system to remove Br-, N-, and O-containing
compounds from degradation oils. 相似文献
17.
Transfer rate of pesticide residues from medicinal plants in different types of extractive solutions
Alexandru Mihai Florea Veronica Drumea Roxana Andreea Nita Adelina Bicu Laura Olariu Ligia Elena Dutu 《毒物与环境化学》2020,102(1-4):37-61
AbstractStarting from the suspicion that the medicinal herbs may contain traces of pesticides and taking into account the risks of patients being exposed to contaminated products, the aim of this research was to evaluate the pesticide residues and the degree of their transfer (%) in three types of preparations (infusion, decoctionand cold maceration), for four medicinal plant species very often used in phytotherapy (Rosmarini folium, Menthae folium, Saturejae herba and Basilica herba). For each type of plant product, four samples were purchased from different manufacturers and they have been analyzed using gas chromatography- tandem mass spectrometry. One out of four samples of the same plant species contain at least one pesticide residue above the maximum level and shows a significant transfer of these residues in aqueous extractive solutions during extraction. The highest rate of pesticide transfer from medicinal plants was identified in infusions, recommended by many manufacturers. 相似文献
18.
Badea O Tanase M Georgeta J Anisoara L Peiov A Uhlirova H Pajtik J Wawrzoniak J Shparyk Y 《Environmental pollution (Barking, Essex : 1987)》2004,130(1):93-98
The results of forest health status assessments in the Carpathian Mountains from the monitoring networks developed by the European Union Scheme on the Protection of Forest Against Atmospheric Pollution (EU Scheme) and International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP-Forests), have led to a better understanding of the impact of air pollution and other stressors on forests at the regional scale. During the period 1997-2001, forests in the Carpathian Mountains were severely affected by air pollution and natural stresses with 29.7-34.9% of the trees included in defoliation classes 2-4. The broadleaves were slightly healthier than the conifers, and European beech (Fagus sylvatica) was the least affected species. Norway spruce (Picea abies) has poor health status, with 42.9-46.6% of the trees damaged (2-4% defoliation classes). Silver fir (Abies alba) damage was also high, with 46.0-50.9% in defoliation classes 2-4. Pines (primarily Pinus sylvestris) were the least affected of the conifers, with 24.9-33.8% in defoliation classes 2-4. The results from the transnational networks (16 x 16 km) show that the Carpathian forests are slightly more damaged than the average for the entire Europe. The correlative studies performed in individual European countries show the relationships between air pollution stressors with trends in defoliation and a possible effect of natural stresses at each site. More specific, effects of tree age, drought, ozone and acid deposition critical level exceedances were demonstrated to affect crown condition. 相似文献
19.
Cornelia Vasile Mihai Adrian Brebu Tammer Karayildirim Jale Yanik Hristea Darie 《Journal of Material Cycles and Waste Management》2006,8(2):99-108
The increasing production of computers, the progress in their performance, and the shorter time between innovation and production
has led to increasing numbers of obsolete products. It has thus become necessary to recover some materials from old computers
and to protect the environment from a new type of pollution. Such recycling is difficult because of the diversity of polymeric
materials used, e.g., thermoplastics (polystyrene or acrylonitrile-butadiene-styrene) and thermosets (epoxy resins), and the
relatively high levels of flame retardants (halogen- and nitrogen-containing compounds) added during production. Pyrolysis
seems to be a suitable way to recover materials and energy from such waste without component separation if an efficient method
for reducing toxic compounds can be applied. In this study, the pyrolysis of plastic and thermoset fractions (keyboards, casings,
printed circuit boards, and mixtures thereof) of used computers was studied by thermogravimetry and batch reactor pyrolysis.
The degradation products were separated into three fractions, solid, liquid, and gaseous, each of them being characterized
by suitable methods such as gas chromatography (GC-MSD, gas chromatography-mass spectrometry detection; GC-AED, gas chromatography-atomic
emission detection), infrared (FT-IR) and 1H-NMR (nuclear magnetic resonanace) spectroscopy, and elemental analysis. It has
been established that most of the halogens, nitrogen, and sulfur is concentrated in the residue. However, the elimination
of hazardous toxic compounds, mainly those containing bromine, is necessary before being able to safely use the pyrolysis
oils as fuels or in refinery or petrochemical industry flows. 相似文献
20.
Elena Bucur Carol Blaziu Lehr Elena Lehr Mihai Nita-Lazar 《Journal of the Air & Waste Management Association (1995)》2017,67(4):391-401
This paper presents a new way to assess the environmental impact on historical artifacts using binary logistic regression. The prediction of the impact on the exhibits during certain pollution scenarios (environmental impact) was calculated by a mathematical model based on the binary logistic regression; it allows the identification of those environmental parameters from a multitude of possible parameters with a significant impact on exhibitions and ranks them according to their severity effect. Air quality (NO2, SO2, O3 and PM2.5) and microclimate parameters (temperature, humidity) monitoring data from a case study conducted within exhibition and storage spaces of the Romanian National Aviation Museum Bucharest have been used for developing and validating the binary logistic regression method and the mathematical model. The logistic regression analysis was used on 794 data combinations (715 to develop of the model and 79 to validate it) by a Statistical Package for Social Sciences (SPSS 20.0). The results from the binary logistic regression analysis demonstrated that from six parameters taken into consideration, four of them present a significant effect upon exhibits in the following order: O3>PM2.5>NO2>humidity followed at a significant distance by the effects of SO2 and temperature. The mathematical model, developed in this study, correctly predicted 95.1 % of the cumulated effect of the environmental parameters upon the exhibits. Moreover, this model could also be used in the decisional process regarding the preventive preservation measures that should be implemented within the exhibition space.
Implications: The paper presents a new way to assess the environmental impact on historical artifacts using binary logistic regression. The mathematical model developed on the environmental parameters analyzed by the binary logistic regression method could be useful in a decision-making process establishing the best measures for pollution reduction and preventive preservation of exhibits. 相似文献