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851.
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
852.
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
853.
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
854.
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
855.
Praveen Linga Rajnish Kumar Ju Dong Lee John Ripmeester Peter Englezos 《International Journal of Greenhouse Gas Control》2010,4(4):630-637
A new apparatus employing a modular, mechanically agitated gas-inducing crystallizer is used to demonstrate the capture of CO2 via hydrate crystallization. The crystallizer enhances the contact of hydrate forming gases with water and thus the rate of hydrate crystallization increases. Flue gas (CO2/N2) and fuel gas (CO2/H2) mixtures were used to represent post- and precombustion capture. A comparison between the rates of hydrate formation in different crystallizers is presented by defining a metric called the normalized rate of hydrate formation. The gas uptake and the separation efficiency for the fuel and flue gas mixtures were found to be greater compared to the results obtained in a smaller scale stirred tank reactor (Kumar et al., 2009c, Linga et al., 2008). The gas uptake and CO2 recovery for flue gas mixture in the presence of THF obtained in this work was higher than that reported in the literature with tetra-n-butyl ammonium bromide and tetra-n-butyl ammonium fluoride (Fan et al., 2009, Li et al., 2009). Although hydrate crystallization is able to capture CO2, the power required for mechanical agitation was found to be very significant. If the hydrate process is to be used industrially then hydrate crystallization must be carried out without mechanical agitation. 相似文献
856.
Lin-Chi Wang Wen-Jhy Lee Wei-Shan Lee 《Environmental pollution (Barking, Essex : 1987)》2010,158(10):3108-3115
Here we show that combustion sources, including waste incinerators, metallurgical processes, power-heating systems and so on, are also important emitters of polybrominated diphenyl ethers (PBDEs) to the atmosphere. Geometric mean PBDE concentrations in the stack flue gases of the combustion sources ranged from 8.07 to 469 ng/Nm3. The sinter plants (24.7 mg/h), electric arc furnaces (EAFs) (11.3 mg/h) and power plants (50.8 mg/h) possessed the largest PBDE emission rates, which were several orders higher than those of the other reported sources. The occurrences of the PBDEs in the flue gases of the power plants and vehicles, as well as their PBDE concentrations statistically highly correlated with combustion-originated PCDD/Fs, revealing that PBDEs should be the products of combustion. The ranking of major PBDE emission sources in Taiwanese PBDE inventory for combustion sources was power plants (30.85 kg/year), vehicles (14.9 kg/year) and metallurgical processes (5.88 kg/year). 相似文献
857.
Man Park Chang-Il Lee Young Jin Seo Sang Ryung Woo Dongill Shin Jyung Choi 《Environmental science and pollution research international》2010,17(1):203-209
Background, aim, and scope
Heavy application of highly toxic synthetic pesticides has been committed to protect crops against insects and diseases, which have brought about serious environmental problems. Thus, an inevitable and fundamental issue has been how to protect crops without harmful effects on nature. As a fascinating nature-compatible approach, we have attempted to hybridize soil-compatible layered double hydroxides (LDHs) with natural antibiotic substances. Only a few of natural antibiotic substances are available for pest control mainly because of their inherent properties such as easy degradability, high minimum inhibition concentration for practical application, and often extremely low availability, whereas LDHs exhibit unique properties such as anion exchange capacity, acid lability, and high affinity to ubiquitous carbonate ion which make them an excellent inorganic matrix to carry labile biomolecules in soils. This study focuses on the behavior of cinnamate–LDH hybrid in soils and the evaluation of its potentials as a green pesticide. 相似文献858.
Jung-Geun Han Jong-Young Lee Ki-Kwon Hong Jai-Young Lee Young-Woong Kim Sun-Mi Hong 《Journal of Material Cycles and Waste Management》2010,12(3):227-234
The aim of the present study was to analytically provide adsorption characteristics of Cu2+ and Zn2+ using carbonized food waste (CFW); more specifically, batch tests were conducted using various concentrations of metal ions, contact times, and initial pH levels in an attempt to understand the adsorption removal of heavy metal ions in aqueous solution at concentrations ranging between 50 and 800 mg/l. The results confirmed that the adsorption equilibrium was established within a maximum of 80 min, and the maximum concentrations for adsorption of Cu2+ and Zn2+ were 28.3 and 23.5 mg/g, respectively. These adsorption levels indicate that CFW has better performance than many other adsorbents. In experiments using different pH conditions, the applicability to acid wastewater was found to be high, and an excellent adsorption removal ratio of 75%–90% was observed under acid conditions at pH 2–4. Furthermore, as the adsorption time increased, the calcium component in the CFW began to leach into the aqueous solution and raise the pH, accordingly causing the removal of heavy metal ions partially as a result of precipitation. When our results were analyzed using the Langmuir model and the Freundlich model for isothermal adsorptivity, the activity of CFW in this study was shown to be more consistent with the former; the adsorption speed of Cu2+ and Zn2+ according to a pseudosecond-order reaction model was found to be very fast for an initial concentration of not more than 100 mg/l. In a test in which an attempt was made to compare adsorption capacity values obtained from the experiments in this study with the aforementioned three models, the pseudosecond-order reaction model was found to provide results closest to the actual values. 相似文献
859.
Ki-Tae Park Byung-Ran Lim Soo-Koo Lee 《Journal of Material Cycles and Waste Management》2010,12(3):235-239
This study was performed to investigate the possibility of utilizing sewage sludge as a fuel. The drying characteristics of sewage sludge were examined by using vacuum evaporation and fry-drying technology in a batch-type rotary evaporator. In addition, the optimal drying conditions of sludge in the vacuum evaporator were investigated in terms of the vacuum pressure, temperature, and oil dosage ratio, etc. Experimental results showed that the moisture content in the sludge decreased with increases in oil/sewage sludge ratio and temperature. Dried sludge fuel (SDF) product could be obtained with on average less than 5% moisture content and a lower heating value of more than 4000 kcal/kg. Considering energy efficiency, we suggest that the optimal operating condition for drying sludge is ?450 mmHg of vacuum, a temperature of 100°C, a drying time of 90 min, and a sludge/oil ratio of 1:1. The SDF product was shaped as granules and fluff-type particles. Evaluated from the perspective of the energy balance and economic considerations, this sludge drying system with vacuum fry drying could be used for effective sludge treatment and the production of SDF. 相似文献
860.