• 한국물환경학회지
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• 제22권5호
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• pp.933-942
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• 2006

In this study, temperature, turbidity, suspended paniculate matter (SPM) distribution and mineral characteristics were investigated to explain spatial distribution of the turbid-water environment of Yongdam reservoir in July, 2005. Six stations were selected along a longitudinal axis of the reservoir and sampling was conducted in four depths of each station. Water temperature was showed the typical stratified structure by the effects of irradiance and inflow. Content of inorganic matter in suspended particles increased with the concentration of suspended particulate matter (SPM) due to the reduction of ash-free dry matter (AFDM). Turbidity ranged from 0.6 to 95.1 NTU and the maximum turbidity value of each station sharply increased toward downstream from upstream. The high turbidity layers were located at the depth between 12~16 m. Particle size ranged from 0.435 to $482.9{\mu}m$. day and silt-sized particles corresponded 91.9~98.9% and 1.1~8.0% in total numbers of SPM, respectively. Turbidity showed high correlations with clay (r=0.763, p<0.05) and silt content (r=0.870, p<0.05).Inorganic matter content (r=0.960, p<0.01) was more correlated with turbidity than organic matter (r=0.823, p<0.05). Mineral characterization using x-ray diffraction and electron probe microanalyzer demonstrated that the major minerals contained in the SPM were kaolinite, illite, vermiculite and smectite. As results of this study, surface water discharge as well as small size of the SPM were suggested as long-term interfering factors in settling down the turbid water in the reservoir.

• 한국대기환경학회지
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• 제25권2호
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• pp.108-121
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• 2009

The suspended particulate matters have been collected on membrane filters and glass fiber filters by an 8-stage cascade impactor for 2 years (Sep. 2005${\sim}$Sep. 2007) in Kyung Hee University-Global Campus located on the border of Yongin and Suwon. The 20 chemical species (Al, Mn, Si, Fe, Cu, Pb, Cr, Ni, V, Cd, Ba, $Na^+$, ${NH_4}^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, ${NO_3}^-$, and ${SO_4}^{2-}$) were analyzed by an ICP-AES and an IC after performing proper pre-treatments of each sample filter. Based on these chemical information, the PMF receptor model was applied to identify the source of ambient size-by-size particulate matters. The receptor modeling is the one of the statistical methods to achieve resonable air pollution management strategies. A total of 10 sources was identified in 9 size-ranges such as long-range transport, secondary aerosol, $NH_{4}NO_{3}$ related source, coal combustion, sea-salt, soil, oil combustion, auto emission, incineration, and biomass burning. Especially, the secondary aerosol source assorted in fine and coarse modes was intensively studied.

• Environmental Engineering Research
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• 제19권4호
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• pp.331-338
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• 2014

Descriptive statistics methods were used to study the spatiotemporal variations and sources of ambient particulate matter ($PM_{10}$) in Luzhou, China. The analyzed datasets were collected from four national air quality monitoring stations: Jiushi (S1), Xiaoshi (S2), Zhongshan (S3), Lantian (S4) over the period of 2003-2012. This city was subjected serious $PM_{10}$ pollution, and the long-term annual average $PM_{10}$ concentrations varied from 76 to $136{\mu}g/m^3$. The maximum concentration was more than 3-fold of the annual average ($40{\mu}g/m^3$) issued by EPA-China for the ambient air quality. General temporal pattern was characterized by high concentrations in winter and low concentrations in summer, and general spatial gradient was in the reduction order of S2 > S4 > S3 > S1, which were both due to different particulate contributors and special meteorological conditions. The source apportionment indicated that vehicular emissions, road dusts, coal burning and chemical dusts were the major contributors of the identified $PM_{10}$ pollution, and the vehicular emissions and the road wear re-suspended particles dominated the heavy $PM_{10}$ pollution in recent years. Two other potential sources, agricultural and celebration activities could decrease the air quality in a short term. Finally, some corresponding suggestions and measures were provided to improve the air quality.

• 한국대기환경학회지
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• 제25권1호
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• pp.46-56
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• 2009

The main purpose of this study was to investigate air quality trends of ambient aerosol with obtaining size-fractionated information. The suspended particulate matters were continuously collected on membrane filters and glass fiber filters by an 8-stage cascade impactor for 2 years (Sep. 2005 $\sim$ Sep. 2007) in Kyung Hee University-Global Campus. 8 ionic species ($Na^+$, ${NH_4}^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, ${NO_3}^-$, and ${SO_4}^{2-}$) were analyzed by an IC after performing proper pretreatments of each sample filter. The average concentration levels of each ion were $9.24{\mu}g/m^3$ of ${SO_4}^{2-}$, $7.35{\mu}g/m^3$ of ${NO_3}^-$, $2.81{\mu}g/m^3$ of ${NH_4}^+$, $2.11{\mu}g/m^3$ of $Ca^{2+}$, $1.65{\mu}g/m^3$ of $Cl^-$, $1.87{\mu}g/m^3$ of $Na^+$, $0.80{\mu}g/m^3$ of $Mg^{2+}$, and $0.54{\mu}g/m^3$ of $K^+$, respectively. The distribution pattern of $Na^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, and ${NO_3}^-$ was bi-modal and two peaks appeared in the range of $0.4{\sim}0.7{\mu}m$ and $3.3{\sim}4.7{\mu}m$, respectively. On the other hand, ${SO_4}^{2-}$, ${NH_4}^+$, and $K^+$ showed patterns of uni-modal distribution, mostly abounded in the fine mode group.

• 한국환경보건학회지
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• 제36권4호
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• pp.306-312
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• 2010

This field study was performed to evaluate the efficiency of a plasma ion-operated air cleaner in temporal reduction of airborne pollutants emitted from a pig housing facility. In the case of gaseous pollutants, the plasma ion air cleaner was not effective in reducing levels of ammonia, hydrogen sulfide, nitrogen dioxide, or sulfur dioxide (p>0.05). In the case of particulate pollutants, however, the air cleaner was effective in reducing levels of particulate matter ($PM_{2.5}$ and $PM_1$) by 79(${\pm}6.1$) and 78(${\pm}3.0$)%, respectively. Unlike the case of these fine particle fractions, the reduction of total suspended particles (TSP) and $PM_{10}$ following treatment was almost negligible. In the case of biological pollutants, the mean reduction efficiencies for airborne bacteria and fungi were relatively low at 22(${\pm}6.6$) and 25(${\pm}8.7$)%, respectively. Taken together, these results indicate that in terms of air pollutants released from this pig housing facility, the plasma ion air cleaner was primarily effective in reducing levels of $PM_{2.5}$ and $PM_1$.

• 생물환경조절학회지
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• 제31권3호
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• pp.237-245
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• 2022

복숭아는 대표적인 여름 과일이자 알레르기를 유발하는 식품으로 밀폐되고 집약적인 생산환경으로 인해 시설 내 유기분진, 농약, 복숭아털이 발생하기 때문에, 열악한 작업환경으로 인한 작업자들이 어려움을 많이 겪고 있다. 본 연구에서는 복숭아 선별작업장에서 발생하는 미세먼지를 위치별, 작업별, 입경별로 모니터링함으로써 저감 및 대책 마련을 위한 기초자료를 확보하고자 하였다. 미세먼지 모니터링 결과 지역별로는 선별과정에서 미세먼지의 발생이 높은 것으로 나타났으며, 주로 기계적인 과정을 통하여 발생하는 10㎛ 이상의 미세먼지로 나타났다. 본 연구를 바탕으로 향후 작업환경의 개선을 위해서 공정 중 미세먼지가 주로 발생하는 지역 및 미세먼지의 물리적 특성을 고려하여 저감시설 및 개인보호구의 착용이 요구된다.

• 한국수산과학회지
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• 제34권4호
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• pp.340-347
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• 2001

한반도 남해안의 고성만과 강진만에 대한 입자유기물질 양과 현탁물식자를 위한 먹이로서의 질의 월별변동을 밝히기 위하여 부유입자물질의 원소 및 생화학 조성에 대한 현장조사를 1999년7월부터 2000년 8월까지 실시하였다. 두 해역의 총 부유입자물질은 해역간에 유사한 농도 분포로 뚜렷한 월별 변동 양식을 나타내지 않았다. 그러나 이들 생물군의 잠재 먹이원인 입자유기물질 조성성분들은 두 해역 모두 여름철에 뚜렷이 높은 농도를 보이는 계절 변동성을 나타내었다. 한편, 입자유기물질의 원소나 생화학 조성 성분의 높은 농도가 나타나는 시기는 chlorophyll a와 잘 일치하여 식물플랑크톤 생산이 입자유기물질의 중요한 조절자라는 것을 가리킨다. 그러나, chlorophyll a와 입자유기물질 조성성분(입자 단백질, 탄수화물 및 지질)들 사이에 유의한 상관관계는 나타나지 않았고, 이들 생화학 성분들 간에도 높은 상관성은 발견되지 않았다 이와 같은 결과들은 식물플랑크톤 생물량이 낮은 시기에 연구 해역들의 입자유기물질에 대한 또 다른 과정들에 의한 기여가 있다는 것을 시사하였는데, 가을에서 봄철사이에 높은 C:Chl a, C:N 비 및 입자 탄수화물의 높은 농도 등은 입자유기물질의 생화학성분 농도가 표층 퇴적물 재부유나 양식생물의 배설과 같은 과정들에 의해 영향을 받고 있다는 것을 나타낸다. 본 조사해역에서 입자유기물질 중 생화학 성분들의 합으로 나타낸 먹이물질은 그것들의 에너지 값과 함께 가을부터 봄철사이에는 다소 높은 농도가 관찰되었지만, 가장 높은 농도는 여름철에 나타났다. 총 부 유입자물질 중 먹이물질이 차지하는 비율로서 표시한 먹이지수는 대체로 $6\%$를 넘지 않는 수준으로 입자유기물질의 영양상태에 있어서 다소 낮은 질을 나타내는 것으로 평가되었다. 본 연구 결과는 식물플랑크톤 변동과 함께 입자유기물질의 먹이물질과 먹이지수 변동을 동시에 측정함으로서 현탁물 섭식자 생물군의 성장과 비만 및 생리생태를 이해하기 위한 자연의 먹이환경으로서 입자유기물질 농도나 질을 더욱 효과적으로 나타낼 수 있다는 것을 보인다.

• 대한원격탐사학회지
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• 제27권2호
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• pp.107-120
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• 2011

동해에서 입자성 유기탄소(Particulate Organic Carbon, POC) 함량을 위성 관측으로 추정하기 위해 MODIS AQUA 위성 자료와 2006~2010 년 춘계와 하계에, 동해 서남부 해역의 30 개 정점에서 화학 분석을 통하여 측정한 POC 함량 자료를 원격 반사도, 확산광소산계수 등 MODIS Aqua 해색 위성 관측 자료와 비교하여 현장 값에 가장 근접하고 통계적으로 유의한 해수 중 POC 함량을 추정하는 알고리즘을 개발하였다. 위성 자료가 현장 값에 가장 근접하는 경우는 $R_{rs}$(488)와 $R_{rs}$(555) 비율을 이용하는 경우로서 거듭 제곱형태로 $POC=266.85^*[R_{rs}(488)/R_{rs}(555)]^{-1.447}$ ($R^2=0.924$)이고, 평균 제곱근 오차는 20.9 mg $m^{-3}$로 양호하였다. 부유 입자 중 POC 이외 물질의 함량은 상기 알고리즘에 영향을 미치지 않는 것으로 나타났다. 그러므로 동해 서남부 해역의 춘계와 하계에 대해서는 이 해역의 광학특성을 반영한 알고리즘을 사용하여 MODIS Aqua 해색 위성 관측 자료로부터 표층 해수의 POC 함량을 추정할 수 있을 것으로 사료된다.

• Water Engineering Research
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• 제1권2호
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• pp.137-146
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• 2000

A windows-based software package, named DREDGE, is developed for estimating sediment resuspension and contaminant release during dredging operations. DREDGE allows user to enter the necessary dredge information, site characteristics, operational data, and contaminant characteristics, then calculates an array of concentration using the given values. The program mainly consists of the near-field models, which are obtained empirically, for estimating sediment resuspension and the far-field models, which are obtained analytically, for suspended sediment transport. A linear equilibrium partitioning approach is applied to estimate particulate and dissolved contaminant concentrations. This software package which requires only a minimal amount of data consists of three components; user input, tabular output, and graphical output. Combining the near-field and far-field models into a user-friendly windows-based computer program can greatly save dredge operator's, planners', and regulators' efforts for estimating sediment transports and contaminant distribution.

• 한국물환경학회지
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• 제26권2호
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• pp.332-342
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• 2010

A model has been developed to investigate in-river sediment and phosphorus dynamics. This advective-dispersive model is coupled with hydrodynamics and sediment transport submodels to simulate suspended sediment, total dissolved phosphorus, total phosphorus, and particulate phosphorus concentrations under unsteady flow conditions. It emphasizes sediment and phosphorus dynamics in unsteady flow conditions, in which the study differs from many previous solute transport studies, conducted in relatively steady flow conditions. The diffusion wave approaximation was employed for unsteady flow simulations. The first-order adsorption and linear adsorption isotherm model was used on the basis of the three-layered riverbed submodel with riverbed sediment exchange and erosion/deposition processes. Various numerical methods were tested to select a method that had minimal numerical dispersion under unsteady flow conditions. The responses of the model to the change of model parameter values were tested as well.