• 한국물환경학회지
• /
• 제31권3호
• /
• pp.313-318
• /
• 2015

To study the influence of changes in river discharge on water quality of the main stem of the Geum River, we investigated variation of inflow load from tributaries with river discharge. We also studied the mixing behavior of pollutants during mixing of waters of the main stem and Gap Stream. For this study, we collected water quality data such as suspended solids (SS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) representing pre-monsoon, monsoon, and post-monsoon events of 2013 from a website of Water Information System. Based on inflow load, the Gap and Miho streams may be ones of tributaries which may largely influence water quality of main stem in upper river region. The Suksung and Nonsan Streams seemed to further affect water quality downstream. Results of modified EMMA indicated SS and TP may have another source(besides Gap Stream) at pre-monsoon, monsoon, and post-monsoon period. In contrast, TN and organic matter (BOD, COD, TOC) were conservative at pre-monsoon and post-monsoon. However, when river discharge increased, these pollutants may also came from unspecified non-point sources. Therefore, we need to attempt to find non-point sources for the pollutants in the main channel of upper Geum River region.

• 한국환경보건학회지
• /
• 제29권1호
• /
• pp.67-73
• /
• 2003

This study was carried out to characterize the behavior and sources of particulate trace metal in Daegu city. TSP (Total Suspended Particulate matter) was collected by filters on High Volume Air Sampler from the four areal (reference, residential, commercial, industrial area). The moult were analyzed by AAS after preliminary treatment. The average centration trend of trace metals contained in TSP was shown as follows : Fe > Cu > Pb > Mn > Ni > Cr > Cd. The trace metals showed the highest concentration in the industrial area. This study showed the seasonal variation of trace metals. Fe and Mn showed high concentration in spring, whereas Cr, Ni, Cd and Pb showed high concentration in winter. Also this study showed the regional variation of trace metals. The order of the average concentration of trace metals was : industrial > commercial > residential > reference area. Using Mn as a reference element, the enrichment factor analysis were used for identifying the trace element contributors. The enrichment factors of Cr, Fe < 10 were considered to have a significant dust and soil source and termed nonenriched. Pb, Cd, Cu >>10 were enriched and had a significant fraction which was contributed by anthropogenic sources.

• 한국대기환경학회지
• /
• 제15권1호
• /
• pp.13-22
• /
• 1999

This study is carried out to investigate the chemical composition of atmospheric deposition in Cheju Island, Korea. For this purpose, dustfall matter samples are collected by dust jar from August, 1995 to July, 1996 at five sampling sites and total suspended particulate matters (TSP) and rain are also collected at one site from October, 1995 to July, 1996. All the samples collected are analyzed, and then the information of the 19 chemical species and deposition amount of each species is obtained. These data are used to determine the regional trends in dustfall chemistry and deposition, and compare the characteristics of chemical compositions between dustfall, TSP and rainwater.

• Environmental Engineering Research
• /
• 제21권3호
• /
• pp.265-275
• /
• 2016

In this study, the microalga Neochloris oleoabundans was cultivated in a sustainable manner using diluted anaerobic digestate to produce biomass as a potential biofuel feedstock. Prior to microalgae cultivation, the anaerobic digestate was characterized and several pretreatment methods including hydrogen peroxide treatment, filtration, and supernatant extraction were investigated and their impact on the removal of suspended solids as well as other organic and inorganic matter was evaluated. It was found that the supernatant extraction was the most convenient pretreatment method and was used afterwards to prepare the nutrient media for microalgae cultivation. A bench-scale experiment was conducted using multiple dilutions of the supernatant and filtered anaerobic digestate in 16 mm round glass vials. The results indicated that the highest growth of the microalga N. oleoabundans was achieved with a total nitrogen concentration of 100 mg N/L in the 2.29% diluted supernatant in comparison to the filtered digestate and other dilutions.

• Safety and Health at Work
• /
• 제15권1호
• /
• pp.114-117
• /
• 2024

A lithium-ion battery is a rechargeable battery that uses the reversible reduction of lithium ions to store energy and is the predominant battery type in many industrial and consumer electronics. The lithium-ion batteries are essential to ensure they operate safely. We conducted an exposure assessment five days after a fire in a battery-testing facility. We assessed some of the potentially hazardous materials after a lithium-ion battery fire.We sampled total suspended particles, hydrogen fluoride, and lithium with real-time monitoring of particulate matter (PM) 1, 2.5, and 10 micrometers (㎛). The area sampling results indicated that primary potential hazardous materials such as dust, hydrogen fluoride, and lithium were below the recommended limits suggested by the Korean Ministry of Labor and the American Conference of Governmental Industrial Hygienists Threshold Limit Values. Based on our assessment, workers were allowed to return to work.

• 한국환경복원기술학회지
• /
• 제21권3호
• /
• pp.99-110
• /
• 2018

Compared to yellow dust coming from China or particulate matter created naturally in spring due to Total Suspended Particulate(TSP), particulate matter in winter season have much more serious effect on human body as they penetrate cell membranes. Although such particulate matter are becoming a social issue, there are no concrete plans on how to reduce them. Air-purifying plants are limited in maintaining the indoor air quality of large area because it is usually difficult to quantify their performance. In order to improve this, a bio-filter that can be connected to air conditioner is suggested as an option. This study seeks to improve air conditioning model-based monitoring method for bio-filters from prior studies and objectify correlations between applied vegetation and growing environment into quantitative indicators. By doing so, this study seeks to provide criteria on plants applied to artificial soil-based vegetation bio-filters and basic information to set air-conditioning features. The study results confirmed significant tendency on the growing stability of each purifying plant in mechanical air-conditioning environment. Among three models selected for bio-filter vegetation models, epipremnum aureum showed high performance in quantitative indicators, including soil moisture, EC, and leaf temperature, etc., indicating that it would assure the highest growing stability in this test air-conditioning environment.

• 한국환경과학회지
• /
• 제21권9호
• /
• pp.1115-1129
• /
• 2012

The objective of this study was to analyze long-term annual and seasonal trends of water chemistry on landuse patterns and seasonal precipitation using 72 sampling sites within Namhan River watershed during 2001-2010. Water quality, based on multi-parameters of water temperature(WT), dissolved oxygen(DO), biochemical oxygen demand(BOD), chemical oxygen demand(COD), suspended solids(SS), total nitrogen(TN), total phosphorus(TP), and electric conductivity(EC) varied largely depending on monsoon rain and landuse patterns such as forest, cropland, and residence. Concentrations of BOD and COD as an indicator for organic matter pollution, increased during summer monsoon season at the cropland and residential streams. Values of TN and TP were higher in residential streams than in the forest and cropland streams. In the meantime, DO values had weak relations to the landuse patterns of forest and cropland cover. Water quality was worst in cropland and residential streams, and also most degradated in 4th order streams. Overall, our results suggest that efficient water quality management is required in the cropland and residential landuse streams.

• 한국해양학회지
• /
• 제5권2호
• /
• pp.52-58
• /
• 1970

하천수는 강수와 이것이 지하에 침투하여 다시 지표에 솟아나온 것으로 이루어지고, 대소의 분,지류가 합쳐져서 하나의 수계를 이룬다. 이러한 과정을 통하여 하천수는 지표 및 지하의 각종 성분을 용해하여 포함하게 되며, 이것으로 말미암아 각 지역별 수계는 독특한 수질적 특성을 자아내게 한다. 이와같은 수계의 지역적인 수질적 특성은 수자원의 종합적 이용면에서 반드시 해명되어야 하는 중요한 사항이고, 또 이것은 우리나라의 지표수의 수질규준설정에 있어서도 꼭 알아두어야 하는 중요한 지견이다.

• 한국대기환경학회지
• /
• 제16권5호
• /
• pp.469-476
• /
• 2000

This study was performed to understand the behavior and source characteristics of particulate trace metals in Daegu area. To do this, total of 84 samples had been collected from January to December 1999. TSP (total suspended particulate matter) and PM-10(particulate matter with aerodynamic diameters less 10${\mu}{\textrm}{m}$) were collected by filters on portable air sampler, and in TSP and PM-10 were analyzed by ICP(Inductively Coupled Plasma Spectrometer) after preliminary treatment. The results were follow as: first, annul means of TSP and PM-10 concentration were 123 and 69$\mu\textrm{g}$/㎤ respectively. The concentration of TSP adn PM-10 were highest in winter season compared to other seasons. Second, the concentration of Al, Fe, Mn were higher in TSP than in PM-10, indicating that these metals are generally associate with natural contributions. Third, a hierarchical clustering technique was used to group 9 metals. The results from the cluster analysis of TSP and PM-10 shows a similar clustering pattern : Fe, Al in a group and the rest of the metals such as Ni, Cr, As, Mn, Cd, Pb, Zn in the other group. One group of metal such as Fe, Al is associated with natural sources such as soil and dust. The other is closely related to urban anthropogenic sources such as fuel combustion, incineration, and refuse burning, Finally, using Al as a reference element, enrichment factors were used for identifying the major particulate contributors. The enrichment factors of Al. Fe<10 (standard value of enrichment factor) were considered to have a significant dust and soil source and termed nonenriched. Ni, Cr, As, Mn, Cd, Pb, Zn》10 is enriched and has a significant which is contributed by athropogenic sources.

• 환경생물
• /
• 제19권2호
• /
• pp.153-157
• /
• 2001

2000년 춘계에 한국 농촌지역인 충남 서산에서 대기부유분진(SPM)과 곰팡이포자의 관계에 대해 조사하였다. 부유분진의 농도는 1차 황사기간(3월 23-24일)에 $199.8\mu{g}\;m^{-3}$, 2차 황사기간(4월 7-9일)에 $249.4\mu{g}\;m^{-3}$, 비황사기간(5월 12-6일)에 $98.9\mu{g}\;m^{-3}$으로 각각 나타났다. 2회의 황사기간들간에 부유분진 농도는 차이를 보였지만 $5\mu{m}$ 정도의 입경 크기를 가지는 조대분진이 2회의 황사기간 모두에서 총 부유분진 양의 대부분을 차지하였다. 그러나 비황사기간의 부유분진 입경분포 그래프는 $1\mu{m}$ 정도의 입경 크기를 가지는 미세분진과 $5-6\mu{m}$ 정도의 크기를 가지는 조대분진이 피크를 보이는 전형적인 bimodal 패턴을 나타내었다. 대기기원 곰팡이포자로부터 성장한 4종류의 사상균류가 황사시기의 부유분진 시료에서 동정되었다. 이들은 Fusarium, Aspergillus, Penicillium, Basipetospora 속으로 확인되었다.