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761.
Kwang Yul Lee Tsatsral Batmunkh Hung Soo Joo 《Journal of the Air & Waste Management Association (1995)》2018,68(8):812-823
The size distribution and chemical components of a fine fraction (<2.5 μm) of road dust collected at urban sites in Korea (Gwangju) and Mongolia (Ulaanbaatar) where distinct urban characteristics exist were measured. A clear bimodal size distribution was observed for the resuspended fine road dust at the urban sites in Korea. The first mode peaked at 100–110 nm, and the second peak was observed at 435–570 nm. Ultrafine mode (~30 nm) was found for the fine road dust at the Mongolia site, which was significantly affected by residential coal/biomass burning. The contribution of the water-soluble ions to the fine road dust was higher at the sites in Mongolia (15.8–16.8%) than at those in Korea (1.2–4.8%). Sulfate and chloride were the most dominant ionic species for the fine road dust in Mongolia. As (arsenic) was also much higher for the Mongolian road dust than the others. The sulfate, chloride, and As mainly come from coal burning activity, suggesting that coal and biomass combustion in Mongolia during the heating season should affect the size and chemical components of the fine road dust. Cu (copper) and Zn (zinc), carbonaceous particles (organic carbon [OC] and elemental carbon [EC]) increased at sites in Korea, suggesting that the fine road dust at these sites was significantly affected by the high volume of traffic (engine emission and brake/tire wear). Our results suggest that chemical profiles for road dust specific to certain sites should be applied to more accurately apportion road dust source contributing to the ambient particulate matter.
Implications: Size and chemical characteristics of fine road dust at sites having distinct urban characteristics were examined. Residential coal and biomass burning and traffic affected physiochemical properties of the fine road dust. Different road dust profiles at different sites should be needed to determine the ambient PM2.5 sources more accurately. 相似文献
762.
Jeong-In Hwang Hyo-Young Kim Sang-Hyeob Lee Se-Yeon Kwak Andrew R. Zimmerman Jang-Eok Kim 《Environmental monitoring and assessment》2018,190(7):438
Prediction of residual concentrations of applied pesticides during the pre-harvest period may be required to ensure the safety of agricultural products. In this study, time-dependent dissipation trends of carbaryl (CB), kresoxim-methyl (KM), flubendiamide (FB), flufenoxuron (FN), bitertanol (BT), and chlorantraniliprole (CN) applied to apples at recommended and threefold greater doses were modeled to estimate pre-harvest residue limit concentrations (CPHRL) indicating permissible pesticide concentrations during the pre-harvest period. Double-exponential (DE) model results best fit the dissipation trends of all tested pesticides (correlation coefficients of 0.91–0.99) compared to zero-, first-, and second-order models. Among the pesticides examined, CB half-lives in apples of 2.9 and 6.6 days were the shortest, while those of FN (21.1–32.7 days) were the longest. The CPHRL values for each pesticide in apples were estimated with DE model parameter values and could be used to determine harvest dates for safe apples with pesticide concentrations below their maximum residue limits. Application of the DE model for CPHRL calculation provides more accurate information for farmers to produce agricultural products safe from pesticide residues. 相似文献
763.
764.
本文首先阐述了TMDL在污染物总量控制中的应用,然后结合特点和存在的不足之处,对我国总量控制技术的实施现状进行了剖析,最后明确提出了水环境污染物总量控制技术实施体系的构建措施,旨在将流域水环境的污染物排放控制在合理范围内,确保良好的控制效果,最大程度地满足环境质量标准。所以现对流域水环境污染物总量控制技术及运用进行详细论述,希望为相关行业人士提供些许帮助。 相似文献
765.
Cui Fangda Zhao Lin Daskiran Cosan King Thomas Lee Kenneth Katz Joseph Boufadel Michel C. 《Environmental Fluid Mechanics》2020,20(6):1553-1578
Environmental Fluid Mechanics - Oil dispersion under a deep-water plunging breaker of height 0.15 m was studied by coupling the Lagrangian particle tracking code (NEMO3D) with the... 相似文献
766.
Xu Guangjian Yang Eun Jin Lee Youngju Kang Sung-Ho 《Environmental science and pollution research international》2020,27(31):38769-38775
Environmental Science and Pollution Research - Multivariate dispersion has proven to be a broad β-diversity measure that shows the heterogeneity of environmental conditions. The dispersion... 相似文献
767.
The Adaptation for Conservation Targets (ACT) Framework: A Tool for Incorporating Climate Change into Natural Resource Management 总被引:1,自引:0,他引:1
MS Cross ES Zavaleta D Bachelet ML Brooks CA Enquist E Fleishman LJ Graumlich CR Groves L Hannah L Hansen G Hayward M Koopman JJ Lawler J Malcolm J Nordgren B Petersen EL Rowland D Scott SL Shafer MR Shaw GM Tabor 《Environmental management》2012,50(3):341-351
As natural resource management agencies and conservation organizations seek guidance on responding to climate change, myriad potential actions and strategies have been proposed for increasing the long-term viability of some attributes of natural systems. Managers need practical tools for selecting among these actions and strategies to develop a tailored management approach for specific targets at a given location. We developed and present one such tool, the participatory Adaptation for Conservation Targets (ACT) framework, which considers the effects of climate change in the development of management actions for particular species, ecosystems and ecological functions. Our framework is based on the premise that effective adaptation of management to climate change can rely on local knowledge of an ecosystem and does not necessarily require detailed projections of climate change or its effects. We illustrate the ACT framework by applying it to an ecological function in the Greater Yellowstone Ecosystem (Montana, Wyoming, and Idaho, USA)-water flows in the upper Yellowstone River. We suggest that the ACT framework is a practical tool for initiating adaptation planning, and for generating and communicating specific management interventions given an increasingly altered, yet uncertain, climate. 相似文献
768.
Guey-Rong Sheu Neng-Huei Lin Jia-Lin Wang Chung-Te Lee Chang-Feng Ou Yang Sheng-Hsiang Wang 《Atmospheric environment (Oxford, England : 1994)》2010,44(20):2393-2400
Measurements of gaseous elemental mercury (GEM), reactive gaseous mercury (RGM), and particulate mercury (PHg) have been conducted at Lulin Atmospheric Background Station (LABS) in Taiwan since April 2006. This was the first long-term free tropospheric atmospheric Hg monitoring program in the downwind region of East Asia, which is a major Hg emission source region. Between April 13, 2006 and December 31, 2007, the mean concentrations of GEM, RGM, and PHg were 1.73 ng m?3, 12.1 pg m?3, and 2.3 pg m?3, respectively. A diurnal pattern was observed for GEM with afternoon peaks and nighttime lows, whereas the diurnal pattern of RGM was opposite to that of GEM. Spikes of RGM were frequently observed between midnight and early morning with concurrent decreases in GEM and relative humidity and increases in O3, suggesting the oxidation of GEM and formation of RGM in free troposphere (FT). Upslope movement of boundary layer (BL) air in daytime and subsidence of FT air at night resulted in these diurnal patterns. Considering only the nighttime data, which were more representative of FT air, the composite monthly mean GEM concentrations ranged between 1.06 and 2.06 ng m?3. Seasonal variation in nighttime GEM was evident, with lower concentrations usually occurring in summer when clean marine air masses prevailed. Between fall and spring, air masses passed the East Asian continent prior to reaching LABS, contributing to the elevated GEM concentrations. Analysis of GEM/CO correlation tends to support the argument. Good GEM/CO correlations were observed in fall, winter, and spring, suggesting influence of anthropogenic emission sources. Our results demonstrate the significance of East Asian Hg emissions, including both anthropogenic and biomass burning emissions, and their long-range transport in the FT. Because of the pronounced seasonal monsoon activity and the seasonal variation in regional wind field, export of the Asian Hg emissions to Taiwan occurs mainly during fall, winter, and spring. 相似文献
769.
Sihye Lee Young Sung Ghim Sang-Woo Kim Soon-Chang Yoon 《Atmospheric environment (Oxford, England : 1994)》2010,44(39):5227-5236
Airborne in-situ measurements were analyzed to investigate the effects of biomass burning and regional background aerosols on cloud condensation nuclei (CCN) activity in the Pacific Dust Experiment (PACDEX) during April and May 2007. Airmass trajectories with both horizontal and vertical motions were provided to identify the aerosol sources. In the biomass burning cases, the elevated aerosol layers were clearly observed at dry conditions because of the convection of airmass in the source region. The relative aging of aerosols was supported by the ratios of BC to particles with size ranging from 0.1 to 1.0 μm (N0.1–1.0) and BC to carbon monoxide. Compared to aerosols in the precedent plume of biomass burning, aged particles in the latter plume were more activated to CCN at 0.4% (CCN0.4%) than 0.1% supersaturation (CCN0.1%) due to aerosols chemical modification during the aging process. On the other hand, significant difference of CCN0.4% and CCN0.1% at regional background aerosols over the Pacific Ocean was due to the activated particles below 1 μm in diameter. Although higher concentrations of aged particles were observed over the eastern Pacific Ocean, activated aerosols to cloud droplet was comparatively similar in the western Pacific Ocean because of the similar concentrations of N0.1–1.0 in both cases. 相似文献
770.
Sung Mo Son Uk Yeong Kim Ik Sang Shin Yong Kang Suk Hwan Kang Byung Tae Yoon Myung Jae Choi 《Journal of Material Cycles and Waste Management》2009,11(2):138-143
The characteristics of bubble properties and the chaotic flow behavior of gas were investigated in an annular fluidized bed
(0.102 m in inner diameter and 2 m in height) because the behavior of gas flow in such a reactor is one of the important factors
governing reactor operation, reactor performance, and the reaction itself. Pressure fluctuations as a state variable for the
analysis of gas flow behavior were measured and analyzed. Bubble properties were determined by adopting the cross-correlation
function of pressure fluctuations. The resultant chaotic flow behavior of gas was interpreted by means of chaotic parameters
such as the Kolmogorov entropy. It was found that the Kolmogorov entropy could be utilized effectively to explain the nonlinear
dynamic behavior of gas-solid flow in the annular fluidized bed. The pierced length and rising velocity of bubbles increased
with increasing gas velocity, bed temperature, and particle size of the bed material. The bubble frequency increased with
increasing gas velocity and bed temperature, while it decreased with increasing particle size of the bed material. Correlations
to predict the bubble properties in annular fluidized-bed reactors were suggested. 相似文献