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991.
Jason A. Roney Bruce R. White 《Atmospheric environment (Oxford, England : 1994)》2006,40(40):7668-7685
Emissions from fugitive dust due to erosion of “natural” wind-blown surfaces are an increasingly important part of PM10 (particulate matter with sizes of 10 μm aerodynamic diameter) emission inventories. These inventories are particularly important to State Implementation Plans (SIP), the plan required for each state to file with the Federal government indicating how they will comply with the Federal Clean Air Act (FCAA). However, techniques for determining the fugitive dust contribution to over all PM10 emissions are still in their developmental stages. In the past, the methods have included field monitoring stations, specialized field studies and field wind-tunnel studies. The measurements made in this paper allow for systematic determination of PM10 emission rates through the use of an environmental boundary layer wind tunnel in the laboratory. Near surface steady-state concentration profiles and velocity profiles are obtained in order to use a control volume approach to estimate emission rates. This methodology is applied to soils retrieved from the nation's single largest PM10 source, Owens (dry) Lake in California, to estimate emission rates during active storm periods. The estimated emission rates are comparable to those obtained from field studies and lend to the validity of this method for determining fugitive dust emission rates. 相似文献
992.
复合型除尘器除尘脱硫一体化工艺实验研究 总被引:2,自引:0,他引:2
试验研究了专利产品“高压静电滤槽复合型卧式除尘器”的除尘脱硫一体化工艺。试验表明,在布袋前方的末级电场中实行半干法脱硫工艺具有可行性,可达到除尘脱硫一体化目的。试验同时研究了钙硫比、脱硫灰循环率、饱和温距、喷水量和SO2浓度等对脱硫率的影响。该工艺适用于以低硫煤为燃料的锅炉进行除尘脱硫。 相似文献
993.
Stasinakis AS Thomaidis NS Giannes AS Lekkas TD 《Environmental science and pollution research international》2003,10(3):177-182
The inhibition effect of arsenite, As(III), arsenate, As(V), inorganic mercury, Hg(II) and methylmercury, MeHg, on the respiration rate of activated heterotrophic sludge microorganisms was evaluated. As(III) and MeHg were much more toxic to activated sludge than As(V) and Hg(II) respectively. The effect of various experimental parameters on the toxicity, such as sludge age, concentration of suspended solids and exposure time, was investigated. An increase of sludge age or the concentration of suspended solids reduces the observed inhibition. Longer exposure seems to dramatically increase the inhibition of As(III), MeHg and Hg(II) during the first hours of exposure, while the later inhibition increases at a slower rate. On the contrary, in the presence of As(V), 24 hours after exposure, the respiration rate was similar to that of the control biomass. 相似文献
994.
995.
996.
本文介绍一种简便、快速的可吸入尘中苯并(a)茈高效液相色谱测定方法.本法仅需5mL乙腈,超声处理10min即可完成提取过程.提取液离心后,上清液可直接进行HPLC分析.色谱条件:反相C18柱,用乙腈/水梯度洗脱,紫外检测器,λ=254nm.方法的最小检出量10~(-10)g.回收率95%,变异系数4、3%.此方法可用于大气可吸入尘中Bap的监测. 相似文献
997.
抗赖氨酸加苏氨酸的玉米种子蛋白突变体 总被引:6,自引:0,他引:6
通过离体选择抗赖氨酸加苏氨酸玉米突变体,不仅获得了积累游离苏氨酸和赖氨酸等氨基酸的突变类型,也选择到了种子蛋白组份发生改变的高蛋氨酸突变体和高赖氨酸体细胞无性系变异体。高蛋氨酸种子中总蛋氨酸的含量比对照增高22.6%,这是由于醇溶蛋白Zein-2部分及其蛋氨酸含量增高所致。高赖氨酸变异体种子游离必需氨基酸增高显著(2-10倍),总赖氨酸比对照亲本增高28.1%,含量约占种子干重的0.40%,种子蛋白清蛋白、球蛋白和谷蛋白组份含量增高而醇溶蛋白减少。高赖氨酸和高蛋氨酸特性遗传稳定,植株育性正常。 相似文献
998.
Influence of industry on the geochemical urban environment of Mieres (Spain) and associated health risk 总被引:4,自引:0,他引:4
Loredo J Ordóñez A Charlesworth S De Miguel E 《Environmental geochemistry and health》2003,25(3):307-323
This study is concerned with the elemental composition of soils and street dust collected in an historical industrial city of approximately 27 000 inhabitants, where old Hg mining and metallurgical activities strongly affected the load of heavy metals in the urban environment. For the purpose of the study, representative samples of soils and street dust were collected at different locations in the whole urban area (3 km2). Elevated mean concentrations of As in soils and street dust (69 and 135 g g–1, respectively), and Hg (3.07 and 4.24 g g–1, respectively), compared to background levels and to those found in other cities, reflect the anomalous geochemical nature of these materials and the strong influence exerted by the old mining sites. 相似文献
1000.
Changes in speciation and mobility of As by indigenous bacteria in As-contaminated sediments (339 mg/kg) from an abandoned
Au–Ag mine area in Korea were investigated after biostimulation with a variety of carbon sources, including acetate, lactate
and glucose in batch experiments. Sequential extraction analysis designed to determine the form of As occurrence revealed
that 40 and 47% of As were present in the sediment as Fe-associated and residual fractions, respectively. After 22-day incubation
with acetate and lactate, the presence of indigenous bacteria increased the amount of total dissolved As from both Fe-associated
and residual fractions in the sediment. More than 99% of dissolved As existed as As(V) in biotic slurries in contrast to sterile
controls (less than 50% of total dissolved As), which indicated that indigenous bacteria transformed some dissolved As(III)
to As(V). In real environments, depending on the pH, microbially-produced aqueous As(V) may be either immobilized through
adsorption or reduced to As(III) after migration to the anoxic subsurface. 相似文献