Chemical characteristics of long-range transport aerosol at background sites in Korea

In this study, background concentration sites of Deokjeok and Gosan, which were deemed suitable for monitoring the impact of long-range transported air pollutants, were selected. An investigation of the source types of pollutants, their locations, and relative quantitative contributions to the particulate concentrations at both sites using appropriate methodologies to make initial estimations was conducted. Episodic measurements of PM_2.5, PM₁₀, and size distribution, along with its ion and carbon components were performed from 2005 to 2007, and a comprehensive analysis of the results was conducted utilizing back trajectory analysis. As for frequency of wind direction, it was quite apparent that the two sites are heavily influenced by air masses originating from the eastern and northern regions of China. For PM_2.5 and PM₁₀, the mass concentrations from north and east China were higher than other cases, originating from the ocean. In the northerly-wind case, meteorological properties for Deokjeok and Gosan and the influence of carbon emissions from northwest Korea resulted in a changing of air mass properties during transport. As was the case with mass concentration, the highest contribution for ionic and carbon components of PM_2.5 and PM₁₀ for both sites appeared for the westerly wind case. A specially high relative contribution, greater than 1.4 times, was apparent in the secondary aerosol case because of a large influence of long-range transported pollutants from east China. Carbon components exhibited different behaviors for the northerly and westerly wind cases compared with secondary aerosol. The major reason for this discrepancy appears to be the carbon emissions from northwest Korea.     

Verantwortungsvoller Umgang mit der Ressource Boden – Workshop zur Erarbeitung eines Aachener Modells für ein nachhaltiges Landmanagement am Niederrhein

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Linear alkylbenzenesulfonates (LAS) of an urban stream in Korea

Profiles of alkyl homologues and isomers of LAS were monitored for an urban stream polluted with municipal wastewaters in Korea. Alkylchains of the stream LAS were shorter than commercial standards and higher I/E ratios were associated with lower LAS concentrations. These suggested a partial biodegradation of LAS in the stream. Higher LAS concentrations were observed in the upper stream. LAS levels were at their lowest during summer probably due to high precipitation and faster biodegradation rates. LAS contributed to about 29% of MBAS and could be used to roughly estimate BOD concentration of the stream.     

Aktuelles aus dem Vorstand

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The acidobasic and complexation properties of Humic acids

Complexation of Humic Acids (HA) of different origin, like Fluka, and especially those extracted from bohemian brown coal, with cadmium(II) and lead(II) was studied at pH 5.0 using differential pulse anodic stripping voltammetry. Conditions close to those present in the environment were chosen with 3‐ 10^‐4 moll^‐4 for HAs and 2. 10^‐8‐l . 10^‐5 moll^‐1 for Cd(II) and Pb(II). Stability constants evaluation was done assuming the electrode process is diffusion controlled and the complexes are labile. Obtained log K values were in the range 4.49–5.25 for Cd(II) and as expected the higher log K values 6.05–6.60 were found for Pb(II). There was no significant difference between complexation properties of HA extracted from bohemian brown coal and that of Fluka. The results obtained are in good agreement with the literature and those obtained by ISE in our laboratory.     

Morphology, molecular phylogeny and photosynthetic activity of the sacoglossan mollusc, Elysia nigrocapitata, from Korea

The morphology, external coloration as well as the life span of a kleptoplastic mollusc, Elysia nigrocapitata, was affected by its algal diet. Among algal diets, Chaetomorpha moniligera was the best for growth but not for animal longevity. TEM studies showed several distinctive layers composed of different cell types in sectioned parapodia. The chloroplast-containing digestive cells were located beneath the layer of vacuolated cells. The digestive cells contained 10–15 chloroplasts, in varying states of intactness, and several nuclei. Chloroplasts were not enclosed by any membranous structure in the host cytosol. Chlorophyll a fluorometry showed that the photosynthetic activity of kleptoplasts in E. nigrocapitata could be maintained for a long time only when animals were kept in the dark. The photosynthetic activity of kleptoplasts lasted 3–4 days when the animals were exposed to continuous illumination of 200 μmol photons m^?2 s^?1. These results suggested that the contribution of kleptoplasts to the survival of the animals might be minimal if the chloroplasts are not sequestered continuously. Cox I, 16S rDNA, and 28S rDNA sequence data have been obtained in order to phylogenetically place the new species of Elysia found in Korea.     

Quantitative ED-EPMA combined with morphological information for the characterization of individual aerosol particles collected in Incheon,Korea

A quantitative single-particle analytical technique, called low-Z particle electron probe X-ray microanalysis, combined with the utilization of their morphological information on individual particles, was applied to characterize six aerosol samples collected in one Korean city, Incheon, during March 9–15, 2006. The collected supermicron aerosol particles were classified based on their chemical species and morphology on a single-particle basis. Many different particle types were identified and their emission source, transport, and reactivity in the air were elucidated. In the samples, particles in the “soil-derived particles” group were the most abundant, followed by “reacted sea-salts”, “reacted CaCO₃-containing particles”, “genuine sea-salts”, “reacted sea-salts + others”, “Fe-containing particles”, “anthropogenic organics”, (NH₄)₂SO₄, “K-containing particles”, and “fly ash”. The application of this single-particle analysis, fully utilizing their chemical compositional and morphological data of individual particles, clearly revealed the different characteristics of the six aerosol samples. For samples S3 and S5, which were sampled during two Asian dust storm events, almost all particles were of soil origin that had not experienced chemical modification and that did not entrain sea-salts during their long-range transport. For sample S1, collected at an episodic period of high PM₁₀ concentration and haze, anthropogenic, secondary, and soil-derived particles emitted from local sources were predominant. For samples S2, S4, and S6, which were collected on average spring days with respect to their PM₁₀ concentrations, marine originated particles were the most abundant. Sample S2 seems to have been strongly influenced by emissions from the Yellow Sea and Korean peninsula, sample S4 had the minimum anthropogenic influence among the four samples collected in the absence of any Asian dust storm event, and sample S6 seems to have entrained air pollutants that had been transported from mainland China over the Yellow Sea to Korea.