Atmospheric Loadings,Concentrations and Visibility Associated with Sandstorms: Satellite and Meteorological Analysis

This Korea-China study monitored the phenomena of sandstorms and significant dustfall (SD) from 1997 to 2000. The analysis of our data included ground measurements of dust concentration, visibility, satellite imagery, aircraft and lidar observations. In addition, an estimation of atmospheric loadings and a studyon the relationship between dust concentrations and visibilitywere carried out. The movement and invasion of dust clouds toKorea were clearly identified with meteorological and satellitedata. The increasing concentrations of TSP and PM₁₀ concurredwell with the satellite information. From case studies, weestimated that atmospheric loadings of a dust cloud were over 1million ton and that the deposition over the Korean Peninsulawas in the range from 46 000 to 86 000 tons. For SD withvisibility of 3 km, we predict TSP 659 g m^-3 and PM₁₀ 493 g m^-3. We recommend the issuance of an SD Watch(advisory) and an SD Warning for the general public.     

BMP IMPACTS ON WATERSHED RUNOFF,SEDIMENT, AND NUTRIENT YIELDS1

ABSTRACT: To quantify the effectiveness of best management practice (BMP) implementation on runoff, sediment, and nutrient yields from a watershed, the Nomini Creek watershed and water quality monitoring project was initiated in 1985, in Westmoreland County, Virginia. The changes in nonpoint source (NPS) loadings resulting from BMPs were evaluated by comparing selected parameters from data series obtained before, during, and after periods of BMP implementation. The results indicated that the watershed-averaged curve number, sediment, and nutrient (N and P) concentrations were reduced by approximately 5, 20, and 40 percent, respectively, due to BMP implementation. The nutrient yield model developed by Frere et al. (1980) was applied to the water quality parameters from 175 storms, but it failed to adequately describe the observed phenomena. Seasonal changes in nutrient availability factors were not consistent with field conditions, nor were they significantly different in the pm- and post-BMP periods. An extended period of monitoring, with intensive BMP implementation over a larger portion of the watershed, is required to identify BMP effectiveness.     

Respirometric Monitoring for the Determination of Effective Height and Reaction Rate Constant in Up-Flow Autotrophic Denitrification Reactor Packed with Sulfur

A novel technology for the removal of nitrogen from wastewater, autotrophic denitrification process with sulfur particle, has been developed. A respirometer was employed for the monitoring of nitrogen gas produced in the reactor. It was found that the autotrophic denitrification studied by gas production rate and nitrate depletion rate followed a first order reaction from the relationship. The reaction rate constant based on effective volume, k_N was ranged from 2.67 to 3.07 h^–1. The effective height was around 23.8 and 50% of the total height for 11.8 and 5.9 h of packed bed contact time, respectively. It was assumed that the reaction rate constants were similar in each experimental condition, PBCT = 11.9 and 5.9 h because there was little gradient of biomass concentration within 50% of the total height. The respirometry was found to be a simple and fast way to monitor the denitrification process. The method was especially useful for the determination of kinetic parameters.     

Use of quadrupole GC-MS and ion trap GC-MS-MS for determining 3-hydroxy fatty acids in settled house dust: relation to endotoxin activity

Gas chromatography-mass spectrometry (GC-MS) using a quadrupole instrument and GC-tandem MS (GC-MS-MS) using an ion trap instrument were applied to determine 3-hydroxy fatty acids (3-OH FAs) with 10-18 carbon chain lengths, specific components of the endotoxin (lipopolysaccharide, LPS) of Gram-negative bacteria, in 30 house dust samples. The two methods provided similar detection sensitivity for methyl ester/trimethylsilyl derivatives of the 3-OH FAs and allowed these acids to be distinguished from co-eluting 2-OH FA derivatives. The correlation coefficients between endotoxin activity (Limulus test) and the combined amounts of 3-OH C10, 3-OH C12, and 3-OH C14 were 0.60 and 0.61 when using GC-MS and GC-MS-MS, respectively. The superior selectivity of GC-MS-MS was illustrated in analyses of sub-milligram amounts of dust, where the chromatograms achieved by GC-MS were difficult to interpret due to a high background and several closely eluting compounds. GC-MS-MS is therefore preferable to GC-MS for determining 3-OH FAs in minute (sub-milligram) amounts of dust.     

A HYDRODYNAMIC MODELING STUDY TO DETERMINE THE OPTIMUM WATER INTAKE LOCATION IN LAKE PALDANG,KOREA1

A three‐dimensional hydrodynamic model was applied to Lake Paldang, South Korea. The lake has three inflows, of which Kyoungan Stream has the smallest flow rate and poorest water quality. Since all drinking water intake stations are located near the confluence of Kyoungan Stream within the lake, this contaminated tributary may have a significant impact on the quality of drinking water sources. The optimum drinking water intake location was determined from the applied model. The model was calibrated and verified using the data measured under different hydrological conditions. The model results were in reasonable agreement with the field measurements in both calibration and verification. The circulation and spreading patterns of the incoming flows in the lake, as well as their composition ratios to the drinking water intakes were determined from the model, and three alternative intake locations were proposed. The simulation results suggested that the horizontal and vertical relocations of the intake aqueduct could significantly decrease the composition ratio of the contaminated water. From this study, it was concluded that the three‐dimensional hydrodynamic model could successfully simulate the temporal and spatial mixing patterns of incoming flows and become a useful tool in determining the optimum water intake location in Lake Paldang.     

A short review on hydrothermal liquefaction of livestock manure and a chance for Korea to advance swine manure to bio-oil technology

Due to the abundant supply and suitable physicochemical characteristics of livestock manure, it may be a useful biomass to produce biofuels, such as “bio-oil.” Hydrothermal liquefaction is a promising method for converting such wet biomasses into a liquid fuels and has attracted attention worldwide. In this review, the current state of research on the hydrothermal liquefaction of livestock manure biomasses is summarized. The effect of operating parameters on the yield of bio-oil is also reviewed. The fundamental characteristics of raw manure biomasses and converted oils are outlined and discussed in the paper. To reduce the use of fossil fuel and nuclear energy, the South Korean government has pledged to increase renewable energy. Based on findings from a literature review, it can be concluded that there is a chance for Korea to advance bio-oil production from the abundant and tremendous energy potential of swine manure by a hydrothermal liquefaction process.     

Development of intelligent sorting system realized with the aid of laser-induced breakdown spectroscopy and hybrid preprocessing algorithm-based radial basis function neural networks for recycling black plastic wastes

Plastic recycling has been the key issue for reducing environmental problems and resolving resource depletion. To improve the recovery rate of plastics, the plastic wastes are correctly identified according to their resin type. However, the identification system, which is able to identify black plastics according to not only the type of black plastics but also the grade of resins correctly, has not been introduced. In this paper, laser-induced breakdown spectroscopy, intelligent algorithms and preprocessing algorithms are used to improve the identification of black plastics such as polypropylene, polystyrene (PS), and acrylonitrile butadiene styrene (ABS). The laser-induced breakdown spectroscopy is capable of obtaining the characteristic spectrum regardless of material’s physical state. To extract the new features which are very valuable to improving learning performance, increasing computational efficiency, and building better generalization models from the obtained spectra through laser-induced breakdown spectroscopy, the hybrid preprocessing algorithm, composed of principal component analysis and independent component analysis, is used. In addition, the intelligent algorithm named the extended radial basis function neural networks inheriting the advantages of fuzzy theory and neural networks is used to identify black plastic samples into several categories with respect to their resins. The proposed identification system, composed of three parts such as laser induced breakdown spectroscopy, hybrid preprocessing algorithms, and an efficient intelligent classification algorithm, is able to show the synergy effect on the black plastic identification problem. From several experimental results, it can be seen that the identification system based on laser-induced breakdown spectroscopy and the intelligent algorithm is used for identification of black plastics by resin type.     

Antecedents and consequences of satisfaction with work–family balance: A moderating role of perceived insider status

This study developed a moderated mediation model to investigate how family‐supportive paid leave and supervision affect employees' satisfaction with work–family balance and in turn their affective organizational commitment and supervisor‐directed organizational citizenship behavior depending on their perceived insider status in the organization. Our analysis of data collected from 118 employee–supervisor dyads in Korean organizations revealed that satisfaction with work–family balance mediated the linkages from family‐supportive supervision to affective organizational commitment and supervisor‐directed organizational citizenship behavior, and the linkage from family‐supportive paid leave to affective organizational commitment. Results further showed that the entire mediational process for family‐supportive supervision was more pronounced for those who perceived themselves to be an insider of their organizations, while the same pattern was not found for the meditational process related to family‐supportive paid leave. Our findings provide theoretical implications for work–family balance research and offer practical suggestions to make employees satisfied with work–family balance.     

Adsorption of mercury by activated carbon prepared from dried sewage sludge in simulated flue gas

Conversion of sewage sludge to activated carbon is attractive as an alternative method to ocean dumping for the disposal of sewage sludge. Injection of activated carbon upstream of particulate matter control devices has been suggested as a method to remove elemental mercury from flue gas. Activated carbon was prepared using various activation temperatures and times and was tested for their mercury adsorption efficiency using lab-scale systems. To understand the effect of the physical property of the activated carbon, its mercury adsorption efficiency was investigated as a function of its Brunauer–Emmett–Teller (BET) surface area. Two simulated flue gas conditions, (1) without hydrogen chloride (HCl) and (2) with 20 ppm HCl, were used to investigate the effect of flue gas composition on the mercury adsorption capacity of activated carbon. Despite very low BET surface area of the prepared sewage sludge activated carbons, their mercury adsorption efficiencies were comparable under both simulated flue gas conditions to those of pinewood and coal activated carbons. After injecting HCl into the simulated flue gas, all sewage sludge activated carbons demonstrated high adsorption efficiencies, that is, more than 87%, regardless of their BET surface area.

Implications: We tested activated carbons prepared from dried sewage sludge to investigate the effect of their physical properties on their mercury adsorption efficiency. Using two simulated flue gas conditions, we conducted mercury speciation for the outlet gas. We found that the sewage sludge activated carbon had mercury adsorption efficiency comparable to pinewood and coal activated carbons, and the presence of HCl minimized the effect of physical property of the activated carbon on its mercury adsorption efficiency.     

Understanding the patterns and processes underlying water quality and pollution risk in West–Africa River using self-organizing maps and multivariate analyses

Environmental Science and Pollution Research - Rivers are dynamic systems in complex interactions with their surrounding environments. Reliable and fast interpretation of water quality is therefore...