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121.
Scholars of environmental injustice have pushed to see beyond the spatial distribution of environmental harms in studies of unwanted land uses. Building upon this work, this article examines how the complex geographies of environmental injustice play out in a coalition to prevent the construction of a coal-fired power plant in Surry County, Virginia. While spatially dispersed coalitions of negatively affected actors can strengthen efforts to prevent the construction of an unwanted land use, they can also perpetuate the environmental injustices surrounding it. To make this argument, particular attention is paid to the diverse reasons and ways differentially situated actors oppose an unwanted land use. It is demonstrated how the disparate concerns and differential tactics deployed by actors in coalitions against unwanted land uses are often embedded in and potentially contribute to longer histories of social injustice. 相似文献
122.
Relationships between stem diameter and phytomass of trees and their parts (single- and multistemmed growth forms) have been studied at different altitudinal levels of the present-day upper treeline ecotone on the Iremel’ Massif, the Southern Urals. The time course of changes in the structure and phytomass of birch–spruce stands during the past centuries has been reconstructed. It is shown that the expansion of forests to the mountains in this period has occurred against the background of rise in summer and winter temperatures and increase in the amount of solid precipitation in the Southern Urals. 相似文献
123.
Daniel Q. Tong Nicholas Z. Muller Haidong Kan Robert O. Mendelsohn 《Environment international》2009,35(8):1109-1117
Human exposure to ambient ozone (O3) has been linked to a variety of adverse health effects. The ozone level at a location is contributed by local production, regional transport, and background ozone. This study combines detailed emission inventory, air quality modeling, and census data to investigate the source–receptor relationships between nitrogen oxides (NOx) emissions and population exposure to ambient O3 in 48 states over the continental United States. By removing NOx emissions from each state one at a time, we calculate the change in O3 exposures by examining the difference between the base and the sensitivity simulations. Based on the 49 simulations, we construct state-level and census region-level source–receptor matrices describing the relationships among these states/regions. We find that, for 43 receptor states, cumulative NOx emissions from upwind states contribute more to O3 exposures than the state's own emissions. In-state emissions are responsible for less than 15% of O3 exposures in 90% of U.S. states. A state's NOx emissions can influence 2 to 40 downwind states by at least a 0.1 ppbv change in population-averaged O3 exposure. The results suggest that the U.S. generally needs a regional strategy to effectively reduce O3 exposures. But the current regional emission control program in the U.S. is a cap-and-trade program that assumes the marginal damage of every ton of NOx is equal. In this study, the average O3 exposures caused by one ton of NOx emissions ranges from ? 2.0 to 2.3 ppm-people-hours depending on the state. The actual damage caused by one ton of NOx emissions varies considerably over space. 相似文献
124.
Qiu Cai Mei-Li Long Ming Zhu Qing-Zhen Zhou Ling Zhang Jie Liu 《Environmental pollution (Barking, Essex : 1987)》2009,157(11):3078-3082
Cadmium (Cd) and Lead (Pb) are environmental pollutants. Environmental samples and bovine tissues were collected from the areas around a lead–zinc smelter in Guizhou, China for Cd, Pb, zinc (Zn) and copper (Cu) analysis. Cd in soil (10 mg/kg) and feed (6.6 mg/kg) from the polluted areas was 10 times higher than the Chinese Standards, resulting in higher Cd in bovine kidney (38 mg/kg) and liver (2.5 mg/kg). Pb in feed (132 mg/kg) from the polluted area was much higher than unpolluted areas, causing higher Pb levels in bovine tissues. Environmental Zn was elevated, but bovine tissue Zn was normal. Cu in bovine liver decreased with increased Cd and Pb. Metals in drinking water and in bovine muscle were within the Standard range. Thus, in the areas of this lead–zinc smelter, the environment has been contaminated with Cd and Pb, which has been transferred to cattle through the food chain. 相似文献
125.
In this paper, Loofa egyptiaca (LE), an agricultural plant cultivated in Egypt, was used to prepare low-cost activated carbon (LEC1 and LEC2) adsorbents. The adsorbents (LE, LEC1 and LEC2) were evaluated for their ability to remove direct blue 106 dye from aqueous solutions. Batch mode experiments were conducted using various parameters such as pH, contact time, dye concentration and adsorbent concentration. The surface chemistry of LE, LEC1 and LEC2 was analyzed by scanning electron microscopy (SEM). The experimental data were examined using Langmuir, Freundlich, Temkin and Harkins–Jura isotherms. The results showed that the adsorption of direct blue 106 was maximal at the lowest value of pH (pH = 2). Removal efficiency was increased with an increase in dye concentration and a decrease in amount of adsorbent. Maximum adsorption capacity was found to be 57.14, 63.3 and 73.53 mg/g for LE, LEC1 and LEC2 respectively. Kinetics were also investigated using pseudo-first-order, pseudo-second-order and intra-particle diffusion models. The experimental data fitted very well with the pseudo-first-order and pseudo-second-order kinetic models. The results indicate that LE, LEC1 and LEC2 could be employed as adsorbents for the removal of direct blue dye from aqueous solutions. 相似文献
126.
Mohammednoor Altarawneh Daniel Carrizo Artur Ziolkowski Eric M. Kennedy Bogdan Z. Dlugogorski John C. Mackie 《Chemosphere》2009,74(11):1435-1443
This article reports the computational and experimental results of the thermal decomposition of permethrin, a potential source of dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF). We have performed a quantum chemical analysis by applying density functional theory to obtain the decomposition pathways of permethrin and the formation mechanism of dibenzofuran. We have conducted the pyrolysis experiments in a tubular reactor and identified the pyrolysis products to demonstrate the agreement between the experimental measurements and quantum chemical calculations. The initiation of the decomposition of permethrin involves principally the aromatisation of permethrin into 3-phenoxyphenylacetic acid, 2-methylphenyl ester (J) and concomitant loss of 2HCl. This rearrangement is followed by the rupture of the O–CH2 linkage in J, with a rate constant derived from the quantum chemical results of 1 × 1015 exp(−68 kcal/mol/RT) s−1 for temperatures between 700 and 1300 K. This is confirmed by finding that the rate constant for unimolecular rearrangement of permethrin into J is 1.2 × 1012 exp(−53 kcal/mol/RT) s−1 over the same range of temperatures and exceeds the direct fission rate constant at all temperatures up to 850 ± 120 °C as well as by the experimental detection of J prior to the detection of the initial products incorporating diphenyl ether, 1-methyl-3-phenoxybenzene, 3-phenoxybenzaldehyde and 1-chloromethyl-3-phenoxybenzene. As the temperature increases, we observe a rise in secondary products formed directly or indirectly (via phenol/phenoxy) including aromatics (naphthalene), biphenyls (biphenyl, 4-methyl-1,1′-biphenyl) and dibenzofuran (DF). In particular, we discover by means of quantum chemistry a direct route from 2-phenoxyphenoxy to naphthalene. We detect no polychlorinated dibenzo-p-dioxins and dibenzofurans. Unlike the case of oxidative pyrolysis [Tame, N.W., Dlugogorski, B.Z., Kennedy, E.M., 2007b. Formation of dioxins in fires of arsenic-free treated wood: Role of organic preservatives. Environ. Sci. Technol. 41, 6425–6432] where significant yields of both PCDD and PCDF were obtained, under non-oxidative conditions the thermal decomposition of permethrin does not form appreciable amounts of PCDD or PCDF and the presence of oxygen (and/or a sizable radical pool) appears necessary for the formation of dibenzo-p-dioxin itself or PCDD/F from phenol/phenoxy. 相似文献
127.
Endosulfan in China 1—gridded usage inventories 总被引:9,自引:0,他引:9
Jia H Li YF Wang D Cai D Yang M Ma J Hu J 《Environmental science and pollution research international》2009,16(3):295-301
Background, aim, and scope Endosulfan, an organochlorine pesticide (OCP), is genotoxic in mammalian cells and generally considered to be toxic and classified
by the World Health Organization and the US Environmental Protection Agency as priority pollutants and a nominator for inclusion
in a future iteration of the persistent organic pollutants treaty. Endosulfan is a currently used pesticide and still being
used worldwide. The general trend of total global endosulfan use has increased continuously since the first year when this
pesticide was applied. It is critical to create national endosulfan usage/emission inventories for China to carry out source–receptor
relation analysis, risk assessment, and other research related to endosulfan in this country. Chinese inventories have been
published for some OCPs, such as technical HCH and lindane, DDT, and chlordane; for endosulfan, however, there has not been
any usage inventory available on any scales (national or provincial), although endosulfan has been widely used since 1994
in this country. This is the first part of the work. The goal of this paper is to quantify the historical production and usage
of endosulfan in China and to compile gridded historical usage inventories of endosulfan for this country. Based on these
usage inventories, emission and residue inventories will be created, which is the goal of the second part of the work.
Materials and methods Due to the lack of national production and usage information of endosulfan in China, a method to estimate the use of endosulfan
was developed. First, information of crops on which endosulfan is applied and average endosulfan use and annual application
frequencies of endosulfan on these crops were collected. Secondly, usage of endosulfan on each crop was estimated using the
national cropland area for each province from Chinese government reports. Finally, with the help of GIS (geographic information
system), the usage data of this insecticide was allocated to a grid system, with a 1/4° longitude by 1/6° latitude resolution,
with a size for each grid cell of approximately 25 km by 25 km.
Results and discussion The use of endosulfan in agriculture in China started on cotton in 1994, and on wheat, tea, tobacco, apples, and other fruits
in 1998. Endosulfan usage on cotton, wheat, tea, tobacco, and apples in China has been estimated to be approximately 25,700 t
between 1994 and 2004. The province with the highest usage of endosulfan is Henan Province, with a total usage reaching 4,000 t,
followed by the uses in Xinjiang Autonomous Region (3,200 t), Shandong Province (3,000 t), Hebei Province (2,100 t), and Anhui
Province (1,900 t). Gridded usage inventories of endosulfan at a 1/4° longitude by 1/6° latitude resolution have been created,
which indicate that the intensive endosulfan use was in the south of Hebei Province, west of Shandong Province, east of Henan
Province, north of Anhui Province, east of Jiangsu Province, and some areas in Yunnan Province and Xinjiang Autonomous Region.
General agreement has been found between the usage data from our estimation and the small amount of usage data published in
China.
Conclusions This is the first national gridded endosulfan usage inventory produced for China. The annual applications of endosulfan from
1994 to 2004 in China were estimated based on the total areas of major crops, on which endosulfan was applied, and spatial
distribution of the application was generated at provincial and prefecture levels. With the help of GIS, endosulfan usage
based on prefecture was transferred to a 1/4° longitude by 1/6° latitude gridding system. The satisfaction of the inventories
was supported by the consistence between the estimation of the annual usage and the reported annual production of endosulfan.
Recommendations and perspectives This gridded endosulfan usage inventory created in this study will be improved upon availability of new information of endosulfan.
The usage inventories can be used to create gridded emission and residue inventories for this insecticide. It is believed
that this work will pave the way for further endosulfan studies in China and beyond. 相似文献
128.
从某印染厂废水排放出口的污泥中分离到一株活性艳蓝X-BR染料高效降解菌LPY68-14,经生理生化鉴定,该菌为埃希氏菌(Escherichia sp.).研究了影响菌株LPY68-14降解效果的因素,实验结果表明:在缺氧、质量分数为0.2%葡萄糖为外加碳源、温度37℃、接种量4 mL、pH 7的最佳条件下,质量浓度为30 mg/L的活性艳蓝X-BR经菌株LPY68-14处理24 h后的降解率可达80%;当活性艳蓝X-BR质量浓度为100~400 mg/L时,该菌处理48 h后的降解率可稳定在70%左右. 相似文献
129.
我国钛白粉工业发展现状与环境政策研究 总被引:1,自引:1,他引:0
针对我国钛白粉工业发展的现状与存在的问题,深入分析造成钛白粉上业现状的原因,并从环保角度提出对策与建议. 相似文献
130.