细化搜索
结果 31-40 的 127
Adsorption, Desorption And Mobility of Fomesafen in Chinese Soils
2003
Guo, Jiangfeng | Zhu, Guonian | Shi, Jianjun | Sun, Jinhe
Fomesafen, 5-[2-chloro-4-(trifluoromethyl)phenoxy]-N-(methylsulfonyl)-2-nitrobenzamide, is used widely for weed control in soybeans since its introduction to China. Little information is available on its adsorption, desorption and movement in Chinese soils. The adsorption, desorption and mobility of fomesafen in six Chinese soils was studied. Adsorption isotherms agreed with the Freundlich equation very well. The results of regressionanalysis indicated that soil pH was more important than organic matter for fomesafen adsorption. Fomesafen was more readily desorbed from soils with 0.01 M CaSO₄solution. Soil TLC and column leaching studies showed that fomesafen and its metabolites was less mobile in Chinese soils. About 89.82% of applied fomesafen and its metabolites still remained in upper 5 cm layer 60 days after treatment under field conditions.
显示更多 [+] 显示较少 [-]An Application of Geographic Information System (GIS) to a Fictitous Thermal Power Plant in Mersin, Türkiye: An Application of Dispersion Modelling Coupled with GIS
2003
Oguz, Mustafa
In this study, local air quality impacts of a proposed conventionalcoal-fired power plant in the İçel region has been investigated using numerical dispersion modeling studies coupled with a GIS application. Within the impact area of the facility, Industrial Source Complex Short Term (ISCST2) dispersion model has been used to estimate ground-level concentrations of air pollutants originating from the power plant. For the same impact area, GIS applications have been utilised to determine the agricultural yield distribution. For this purpose, relevant satellite images were digitised, classified and statistically analyzed. Based on the predicted ground-level pollutant concentrations and sensitivity of the agricultural crops to the pollutants, agricultural yield loss was estimated for the impact area.The results have been quantified and valuated in monetary terms for the purpose of performing an environmental cost benefit analysis. Comparison of the conventional cost benefit analysis with the environmental cost benefit analysis showed the significance of the external cost of the proposed facility, resulting from the environmental damages.
显示更多 [+] 显示较少 [-]Development of a Multi-Resolution Emission Inventory and Its Impact on Sulfur Distribution for Northeast Asia
2003
Woo, J.-H. | Baek, J. M. | Kim, J. W. | Carmichael, G. R. | Thongboonchoo, N. | Kim, S. T. | An, J. H.
Emissions in East Asia for 1993 by administrative units and source types are estimated to support regional emission assessments and transport modeling studies. Total emission of SOₓ, NOₓ, soil NOₓ, N₂O, and NH₃are 24 150, 12 610, 1963, 908, and 8263 kton yr⁻¹, respectively.China's emission contribution is the highest for every species.The area sources are the most significant source type for SOₓand NOₓ, but the fraction due to mobile source is highest for NOₓ. Major LPSs are located from the middle to the east part of China, south and middle-west part of South Korea, and the east part of Japan. The area sources of SOₓshow a pattern similar to population density, whereas NH₃shows a strong landuse dependency. Detail emissions analysis reveals higher SOₓemission `cores' within each province. The estimated emissions are used to estimate sulfur deposition in the regions. The seasonal average sulfur distribution amounts are estimated from the ATMOS2 chemical transport model. The results showed anti-correlation with temperature for sulfur (SO₂+ SO₄⁻²) concentrations and a positive correlation with rainfall for deposition.
显示更多 [+] 显示较少 [-]Physical and Chemical Characteristics of Urban Snow Residuals Generated from Traffic Activities
2003
Sansalone, John J. | Glenn III, Donald W. | Tribouillard, Thierry
Urban transportation activities generate a wide gradation of anthropogenic solids with varying physical and chemical properties. These solids accumulatein urban highway snow and remain as residual deposition material after the melting and recession of the snow from the pavement shoulder. This study analyzed the physical characteristics of these residuals and the associatedheavy metals for 10 urban highway sites located throughout metropolitan Cincinnati. Results from the residuals analyses indicate that for all sites particle gradations ranged from greater than 5000-μm to less than 25-μm with a mean d₅₀of 1225-μm. Specific gravity (ρₛg) of residual solids ranged from 2.5 to 3.2 as evaluated for intervals across thegradations, with the lower specific gravity associated with particles less than 100-μm. For each gradation, specific surface area (SSA) generally increased with decreasing particle size while the predominance of total surface area (SA) was associated with the coarser size fractions. Cumulativeanalysis for Pb, Cu, Cd and Zn associated with snow residuals indicated that more than 50% of the heavy metal mass was associated with particles greaterthan 250-μm and more than 80% was associated with particles greater than 50-μm. Results provide guidance for management of urban snow residuals and design of treatment strategies focused on these residuals.
显示更多 [+] 显示较少 [-]Removal of Mercury Ions from Mixed Aqueous Metal Solutions by Natural and Modified Zeolitic Minerals
2003
Gebremedhin-Haile, T. | Olguín, M. T. | Solache-Ríos, M.
Research works on the removal of mercury from water by zeolitic mineralshow that small quantities of this element are sorbed. In this work the mercury sorption from aqueous solutions in the presence and absence of Cu(II), Ni(II) and Zn(II) onto a Mexican zeolitic mineral unmodified and modified with cysteamine hydrochloride or cystamine dihydrochloride was investigated in acidic pH. The zeolitic minerals were characterized by thermogravimetric analysis, scanning electron microscopy, X-ray diffraction and FTIR. The sorption kinetics behavior and the retention isotherms for mercury were determined in the natural and treated zeolitic mineral samples. It was found that the amounts of sulfur on the modified zeolitic minerals were 0.375 (cysteamine hydrochloride) and 0.475 (cystamine dihydrochloride) mmol g⁻¹, which were not saturated to their total capacities of adsorption for the maximum concentration used (0.310 mM). Under the experimental conditions, the retention of mercury was the highest for the zeolitic minerals treated with the organic compounds, with adsorption capacities ranging from 0.0107 to 0.0509 mmol Hg g⁻¹.The retention was not affected by the presence of others heavy metals studied in this work as expected.
显示更多 [+] 显示较少 [-]Application of Bioassays for Risk Characterisation and Remediation Control of Soils Polluted with Nitroaromatics and PAHs
2003
Rila, Jean-Paul | Eisentraeger, Adolf
Six soil samples taken from three contaminated sites have been assessed using chemical, ecotoxicological and genotoxicological methods. From two of these sites, samples were characterised after remediation. An overall assessment of the soil samples was done with a scheme consisting of two phases. Remediation of main pollutants in these samples, did in general not lead to a risk reduction of the water-extractable ecotoxic and genotoxic potential. It was concluded, that the assessment and remediation of contaminated sites without consideration of biological test systems is not sufficient. Focussing on single hazardous compounds does in many cases not lead to a reduction of the ecotoxic or genotoxic potential. Consequently, effects of accompanying hazardous compounds, which are not routinely quantified, might be underestimated. It was pointed out, that the assessment of contaminated soil samples on the basis of LID-values applying dual dilution series seems to be sufficient for the evaluation, if there is no need for a quantitative comparison of toxic potentials.
显示更多 [+] 显示较少 [-]Summertime evolution of ozone in the high Arctic
2003
Schulz, Astrid | Krieg, J. | Notholt, Justus | Lehmann, Ralph
Chemical degradation methods for wastes and pollutants
2003
Tarr, Matthew A.
Characteristics of different solid PSC particles observed by lidar in Ny-Aalesund
2003
Müller, Marion | Neuber, Roland | Fueglistaler, S.
Progress in observations of polar stratospheric clouds
2003
Remedios, J. | Spang, R. | Luo, B. | Adriani, A. | Carslaw, K. | Larsen, N. | Neuber, Roland | Newnham, D. | Peter, T.