간행물
한국환경과학회지 KCI 등재 Journal of Environmental Science International
- 발행기관 한국환경과학회
- 자료유형 학술지
- 간기 월간
- ISSN 1225-4517 (Print)2287-3503 (Online)
- 수록기간 1992 ~ 2023
- 주제분류 자연과학 > 자연과학일반 자연과학 분류의 다른 간행물
- 십진분류KDC 539DDC 628
권호리스트/논문검색
제22권 제1호 (2013년 1월) 13건
ORIGINAL ARTICLE
1.
2013.01
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A fixed biofilm reactor system composed of anaerobic, anoxic(1), anoxic(2), aerobic(1) and aerobic(2) reactor was packed with synthetic activated ceramic (SAC) media and adopted to reduce the inhibition effect of low temperature on nitrification activities. The changes of nitrification activity at different wastewater temperature were investigated through the evaluation of temperature coefficient, volatile attached solid (VAS), specific nitrification rate and alkalinity consumption. Operating temperature was varied from 20 to 5 ℃. In this biofilm system, the specific nitrification rates of 15 ℃, 10 ℃ and 5 ℃ were 0.972, 0.859 and 0.613 when the specific nitrification rate of 20 ℃ was assumed to 1.00. Moreover the nitrification activity was also observed at 5 ℃ which is lower temperature than the critical temperature condition for the microorganism of activated sludge system. The specific amount of volatile attached solid (VAS) on media was maintained the range of 13.6-12.5 mg VAS/g media at 20~10 ℃. As the temperature was downed to 5 ℃, VAS was rapidly decreased to 10.9 mg VAS/g media and effluent suspended solids was increased from 3.2 mg/L to 12.0 mg/L due to the detachment of microorganism from SAC media. And alkalinity consumption was lower than theoretical value with 5.23 mg as CaCO3/mg NH4 +-N removal at 20 ℃. Temperature coefficient (θ) of nitrification rate (20 ℃ ~ 5 ℃) was 1.033. Therefore, this fixed film nitrogen removal process showed superior stability for low temperature condition than conventional suspended growth process.
2.
2013.01
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Aerosol characterization study for individual particle in Busan metropolitan industrial complex was carried out from December 2010 to August 2011. SEM(scanning electron microscope)-EDX(energy dispersive x-ray) analysis was used for the analysis of 600 single particles during the sampling periods to identify non-metallic aerosol particle sources. Average PM10 concentration was 65.5 ㎍/㎥ in summer, 104.1 ㎍/㎥ in winter during the sample periods. And Average PM2.5 concentration was 24.5 ㎍/㎥ in summer, 64.5 ㎍/㎥ in winter individually. Particle density, enrichment factor, correlation analysis, principle component analysis were performed based on chemical composition data. Particle density distribution was measured to 2∼4 g/㎤, and the density of PM2.5 was measured above 3 g/㎤. In general, the elements Si, Ca, Fe and Al concentrations were higher in all samples of individual particles. The non-ferrous elements Zn, Br, Pb, Cu concentrations were higher in summer than in winter. The concentrations were not changed with the seasons because of non-ferrous industry emission pattern.
3.
2013.01
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In order to evaluate the effect of various organic soil conditioner ratios on the soil moisture content and growth of Cotoneaster horizontalis, a container type for wall-planting experiment was conducted in a greenhouse at Konkuk University under non-irrigation. The experimental planting grounds were prepared with different organic soil conditioner ratios (A1L0, A8L1, A4L1 A2L1 and A1L1), and a drought-tolerant ornamental variety of Cotoneaster horizontalis was planted. The change in soil moisture content, plant height, number of branches, number of dead leaves, number of leaves, number of shoots, length of node, length of leaf, width of leaf, root-collar caliper, chlorophyll content, and survival rate were investigated, from April to Jun 2010.
The results of soil moisture content measurements were analyzed with weight units in the container type for wall-planting during the dry summer season. The soil moisture contents were significantly enhanced in the container type for wall-planting in increasing order as the amount of soil conditioner level was increased (A1L1> A2L1> A4L1> A8L1> A1L0). Compared to the control treatment application (amended soil with 100% + organic soil conditioner 0%), the highest plant growth was observed in the treatment of A1L1 application (amended soil with 50% + organic soil conditioner 50%). However, the differences between the organic soil conditioner ratio treatments of A1L1, A4L1, and A8L1 organic soil conditioner application were mostly not significant. The survival rate increased with the increasing application of organic soil conditioner, but in the control treatment application all the plants died.
The experimental results from clearly demonstrated that the organic soil conditioner improved the survival rate more than the growth of Cotoneaster horizontalis. Therefore, Cotoneaster horizontalis is expected to be a highly valuable shrub for green wall systems, when considered for us in integration system or for increasing soil water contents in planting grounds.
4.
2013.01
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The concentration of organic compounds was analyzed at each step of BAC process though BDOCtotal/rapid/slow. Further, bacteria communities and biomass concentrations measured FISH and ATP methods were analyzed. The bed volume (BV) of steady state is different from that of based on assessment of organic compounds removal. Bed volumes in DOC, BDOCrapid and BDOCtotal/slow removal at steady state were around 27,500 (185.8 day), 15,000 (101.4 day) and 32,000 (216.2 day), respectively. A biomass didn't change after the bed volume reached 22,500 (152.0 day) according to analyzing ATP concentration of bacteria. The concentration of ATP was 2.14 μg/g in BV 22,500 (152.0 day). The total bacterial number was 4.01±0.4×107 cells/g at the bed volume 1,150 (7.8 day) (the initial operation) and the number of bacteria was 9.27±0.2×109 at the bed volume 58,560 395.7 day) that increased more than 200 times. Bacterial uptrend was reduced and bacterial communities were stabilized since BV 18,720 (126.5 day). When BV were 1,150 (7.8 day), 8,916 (60.2 day), 18,720 (126.5 day), 31,005 (209.5 day), 49,632 (335.3 day), 58,560 (395.7 day), a proportion of total bacteria for the Eubacteria were 60.1%, 66.0%, 78.4%, 82.0%, 81.3% respectively. γ-Proteobacteria group was the most population throughout the entire range. The correlation coefficient (r2) between Eubacteria biomass and ATP concentration was 0.9448.
5.
2013.01
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The monthly variations of blood characteristics and RNA/DNA of black sea bream, Acanthopagrus schlegeli, habituated in Geojae costal area were analysed to determine health condition of natural stocks in terms of gonad maturation and spawning season from March 2010 to February 2011. Spawning season determinated by gonadosomatic index is from June to August. RNA/DNA ratio of black sea bream muscle was strongly correlated with spawning season. During the gonad maturation RNA/DNA ratio in dorsal muscle tissue was decreased contrast to rapid increase during spawning season. Blood composition factors increased in terms of gonad maturation are aspartate aminotransferase, cholesterol, triglyceride, total protein, glucose, globulin, alkaline phosphatase and inorganic phosphate. Other blood factors increased during spawning season are alanine aminotransferase, blood urea nitrogen, uric acid and lactate dehydrogenase.
6.
2013.01
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Studies evaluating the health effects of hazardous air pollutants assume that people's exposure to typical pollutant level is the same as specific regional pollutant level. However, depending on social and demographic factors, time-activity pattern of people can vary widely. Since most people live in indoor environments over 88% of the day, evaluating exposure to hazardous air pollutants is hard to characterize. Objective of this study was to estimate the exposure levels of university students of NO2, VOCs(BTEX) and PM10 using the scenarios with time-activity pattern and indoor concentrations. Using data from time-use survey of National Statistical Office in 2009, we investigated time-activity pattern of university students and hourly major action. A total of 1,057 university students on weekday and 640 on weekend spent their times at indoor house 13.04 hr(54.32%), other indoors 7.70 hr(32.06%), and transportation 2.36 hr(9.83%). Indoor environments in which university students spent their times were mainly house and school. Air pollutants concentrations of other indoor environments except house and school such as bar, internet cafe and billiard hall were higher than outdoors, indicating that indoor to outdoor ratios were above 1. According to three types of exposure scenarios, exposure to air pollutants could be reduced by going home after school.
7.
2013.01
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The purpose of this study is to assess the effects of heavy metal concentrations in the blood and urine of the general population. This research had been conducted from April to December 2008, studying 545 residents of Daejeon and Chungcheong Province. Through the concentrations of heavy metals(Pb, Cd, Hg, As, Mn) in the biota samples and questionnaires, the residents heavy metal exposure level and the influential factors according to personal characteristics or lifestyle were evaluated. As to the heavy metal concentration in the blood and urine of the comparing region, were As and Mn statistically significant(p<0.01, p<0.05). Blood lead and urinary mercury concentrations were higher in males than females. The heavy metal concentration for each age group increased blood mercury. The concentration of all heavy metals were higher in the drinkers than in the non-drinkers. Blood lead and mercury concentrations were higher in the smokers than in the non-smokers, but the urinary cadmium, arsenic and blood manganese was higher in the non-smokers than in the smokers. As to the blood lead and urinary cadmium concentration according to the food preference fish showed high concentration. To clarify the factors affecting the heavy metal concentration in biota among subjects multiple regression analysis was conducted. As a results, it turned out that as to lead content in blood, sex, age and smoking have influence on the subjects with explanatory adequacy of 14.0 %. These results demonstrated that the factors affected the concentrations of heavy metals in blood and urine. The results of this study could be used as the foundational data for setting the health risk assessment.
8.
2013.01
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The present work has been devoted to the catalytic reduction of N2O by H2 with Pt/SiO2 catalysts at very low temperatures, such as 110oC, and their nanoparticle sizes have been determined by using H2-N2O titration, X-ray diffraction(XRD) and high-resolution transmission electron microscopy(HRTEM) measurements. A sample of 1.72% Pt/SiO2, which had been prepared by an ion exchange method, consisted of almost atomic levels of Pt nanoparticles with 1.16 nm that are very consistent with the HRTEM measurements, while a Pt/SiO2 catalyst possessing the same Pt amount via an incipient wetness technique did 13.5 nm particles as determined by the XRD measurements. These two catalysts showed a noticeable difference in the on-stream deN2O activity maintenance profiles at 110℃. This discrepancy was associated with the nanoparticle sizes, i.e., the Pt/SiO2 catalyst with the smaller particle size was much more active for the N2O reduction. When repeated measurements of the N2O reduction with the 1.16 nm Pt catalyst at 110oC were allowed, the catalyst deactivation occurred, depending somewhat on regeneration excursions.
9.
2013.01
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Silicon carbide with aluminium oxide was used to remove the sulphur hexafluoride (SF6) gas using microwave irradiation. The destruction and removal efficiencies (DREs) of SF6 were studies as a function of various decomposition temperatures and microwave powers. The decomposition of SF6 gas was analyzed using GC-TCD. XRD (X-ray powder diffraction) and XRF (X-ray Fluorescence Spectrometer) were used to characterize the properties of aluminum oxide. DREs of SF6 were increased as the microwave powers were increased. Additive aluminium oxide on SiC increased the removal efficiencies and decreased the decomposition temperature. The XRD results show that the γ-Al2O3 was transformed to α-Al2O3 during SF6 decomposition by microwave irradiation. It was found that the best material to control SF6 was SiC with Al2O3 30 wt% in consideration of microwave energy consumption and SF6 decomposition rate.
10.
2013.01
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In order to study the seasonal patterns and possible origins of air concentrations of volatile organic compounds(VOC), measurements were taken with GC-MS at 3 sampling sites in Jinju for 12 months from Mar. 2010 to Feb. 2011. Atmospheric VOC are sampled on tubes containing solid adsorbents(Tenax TA) with a time resolution of 2hrs. Composition and concentration of VOC are analysed with a GC system equipped with thermal desorption apparatus(ATD).
The most abundant compound appeared to be Toluene, Ethylbenzene and m,p-Xylene. The mean concentrations of Benzene were 0.20 ppb at GN site, 0.18 ppb at DA site, and 0.25 ppb at SP site, respectively. VOC concentration showed a strong seasonal variation, with higher concentrations during the spring and lower concentrations during the summer. The results showed that monthly fluctuations in measured VOC concentrations depended on variations in the strength of sources, as well as on photochemical activity and meteorological conditions. In Jinju, the total VOC emissions for 2009 were estimated to be 4,407 ton/year by Clean Air Policy Support System(CAPSS). It is shown that solvent use 57.5%(2,534 ton/yr), waste treatment and disposal 23.3%(1,025 ton/yr), and mobil source-road traffic 12.2%(537 ton/yr) are the most significant anthropogenic source.
11.
2013.01
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This study surveyed the distribution and characteristics of epiphytes and host trees in Jejudo’s warm-temperate evergreen forests area. The gathered data will be used for evaluating ecological changes according to climate change. The study found 46 species of epiphytes in Jejudo; 12 of which were species of pteridophytes and 5 species of orchids, totaling 17 species of epiphytes. The appearance frequency was the greatest with Lepisorus thunbergianus, followed by Lemmaphyllum microphyllum and Lepisorus onoei. The area with the greatest diversity of epiphytes was nutmeg tree forests which have the largest number of 2.89 average species. Lemmaphyllum microphyllum had the greatest percent cover of the epiphytes whose importance was found to be the greatest. The factors involved were the epiphytes' diversity index (0.64), maximum species diversity (1.23), evenness (0.52), and dominance (0.48). The study has noted the distribution characteristics of epiphytes according to altitudes above sea level. The Lemmaphyllum microphyllum can survive at an altitude of 600 m above sea level, Lepisorus thunbergianus at 200–1,400m above sea level, Lepisorus onoei. at 400–1,000 m, and Gonocormus minutus at an altitude above 800 m. The host trees, consisting of Quercus serrata, Castanopsis cuspidata var. sieboldii, and Carpinus laxiflora, stands at 2–19 m high and 2.5–120 ㎝ wide, showing diverse kinds of trees and sizes. Jejudo’s warm-temperate evergreen forests have lower epiphyte diversity compared with those of subtropical and tropical areas in Japan and China. Based on the characteristics of the host trees order, epiphytes' distribution associated with the altitude above sea level was typical.
12.
2013.01
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The removal characteristics of composite odor and malodorous substances using 33 biofilters in sewage treatment facilities were investigated. The geometry mean values of composite odor and odor quotient were reduced by 52.7% and 59.2% at the outlet of the biofilters, respectively. The removal efficiencies of the biofiltes for the composite odor and odor quotient show a significant difference statistically(p=0.000<0.05). The median value of odor quotient of sulfur compounds was reduced by 69.1% at the outlet of the biofilter and the odor quotient of the sulfur compound at the inlet and outlet of the biofilter shows a significant difference statistically(p=0.000<0.05); on the other hand, those of the NH3 and trimethylamine, aldehydes, VOCs and alcohols, organic acids do not.
13.
2013.01
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We compared equilibrium evaporation(Eequili) eddy-covariance(Eequili) with soil moisture data(ESMseries) which were measured with a 2 hours sampling interval at three points for a humid forest hillslope from May 5th to May 31th in 2009. Accumulations of Eeddy, Eequili for the study period were estimated as 2.52, 3.28 mm and those of ESMseries were ranged from 1.91 to 2.88 mm. It suggested that the eddy-covariance method considering the spatial heterogeneity of soil evaporation is useful to evaluate the soil evaporation. Method A, B and C were proposed using mean meterological data and daily moisture variation and the computations were compared to eddy-covariance method and equilibrium evaporation. The methods using soil moisture data can describe the variations of soil evaporation from eddy-covariance through simple moving average analysis. Method B showed a good matched with eddy-covariance method. This indicated that Dry Surface Layer (DSL) at 14:00 which was used for method B is important variable for the evaluation of soil evaporation. The total equilibrium evaporation was not significantly different to those of the others. However, equilibrium evaporation showed a problem in estimating soil evaporation because the temporal tendency of Eequili was not related with the those of the other methods. The improved understanding of the soil evaporation presented in this study will contribute to the understandings of water cycles in a forest hillslope.
