• 한국대기환경학회지
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• 제22권4호
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• pp.477-486
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• 2006

Dry deposition fluxes for $SO_2$, particulate sulfate, nitrate, ammonium and $HNO_3$ were estimated in urban area for the time period January$\sim$ October 2005. Fluxes were generated using atmospheric concentration data collected both in Acid Deposition and Air Quality Monitoring Networks, and deposition velocities computed by combining land-use data with meteorological information. The resulting annually averaged $SO_2$, $NO_3$, and aerosol deposition velocities were found to be 0.4 cm/s, 4.3 cm/s and 0.1 cm/s, respectively, and thus deposition rates were 4.4 mg/$m^2$. day for $SO_2$, and 5.4 mg/$m^2$ . day for $NHO_3$, and particulate sulfate, ammonium and nitrate recorded 1.0 mg/$m^2$ . day, 0.4 mg/$m^2$ . day and 0.4 mg/$m^2$ day, respectively. Maximum for in seasonal variation of monthly averaged deposition velocities occurred in summer in contrast to $HNO_3$ showing peak in spring. There was no significant variation for aerosol. The dry to total (wet and dry) deposition contributed about 40% for sulfur and 28% for nitrogen species in this study.

• 한국대기환경학회지
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• 제12권1호
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• pp.101-112
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• 1996

Dry and wet deposition is an impertant removal mechanism of the amobient aerosol in the atmospheric environment. Since the deposition flut provides adverse impacts on various encironmental media including aquatic and ecological system as well as human health, it is essential to quantitatively estimate the removal fluxes of many air pollutants. Thus, the purposes of this experimental study are to investigate seasonal deposition flux variations of the total dustfall and various inorganic elements in the local ambient air and then to finally estimate their dry deposition velocities. To perform the study, the total of 90 dustfall samples were collected from January, 1994 thru February, 1995 in 5 different cities of Korea including Seoul, Suwon, Daejon, Kwangju, and Kangrung. Each sample was analyzed by an AAS and an ICP to determine the quantities of the 11 inorganic elements, such as Zn, Cd, Cr, K, Na, Pb, Ca, Fe, Mn, Mi, and Cu. As results, deposition fluxes, soluble/insoluble fractions, and deposition velocities for each element were extensively investigated. The resulting dry deposition velocities of some elements in Suwon were estimated by ranges of 0.57 .sim. 0.87 cm/sec for Zn, 0.35 .sim. 0.45 cm/sec for Pb, 1.25 .sim. 3.52 cm/sec for Ca, 0.21 .sim. 0.48 cm/sec for Fe, 0.95 .sim. 9.31 cm/sec for Mn, and 2.08 cm/sec for Cu.

• 한국환경과학회지
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• 제10권1호
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• pp.1-8
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• 2001

This study was carried out estimating the dry deposition flux of $SO_2$at eight urban areas in Korea during one year of 1996. To calculate the deposition flux, deposition velocities were calculated by turbulence parameters estimated from routine meteorological data. Also, hourly averaged $SO_2$concentrations which calculated from air pollution monitoring data of each city were used. The dry deposition velocities were mostly higher in the coastal areas than the other areas, which would be caused by relatively strong wind. And, they were high in the daytime because of turbulence activities. The deposition flux of $SO_2$is mainly related to the atmospheric concentration. The annual average $SO_2$concentration and the deposition flux were 22.62ppb and 1510.52g/$\textrm{km}^2$/hr at Pusan respectively. Also, the flux was higher in winter than other season, which was a significant contribution of exhausted fuel for heating. While the deposition velocity was high to 0.688cm/sec at Yosu in case of strong wind and small cloud cover, the deposition flux was high to 1597.4g/$\textrm{km}^2$/hr at Pusan in case of weak wind and small cloud cover.

• 한국입자에어로졸학회지
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• 제5권4호
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• pp.179-188
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• 2009

The dry deposition fluxes of particulate polychlorinated biphenyls (PCBs) were measured along with their mass size distributions at Seoul and Incheon in fall in 1999. The dry deposition fluxes of PCBs were in the range of $16.7{\sim}62.2ng/m^2/day$. The ambient concentrations of particulate PCBs were in the range of 0.07 to $0.20ng/m^3$. Generally, the mass size distribution of particulate PCBs shows bi-modal distribution. The mass fraction of PCBs in the fine particle fraction ($D_p<2.1 {\mu}m$) was over than 55% of the total PCBs concentrations. It was found that Seoul and Incheon were not the major source of PCBs emissions in Korea. Based on the comparison with the measurement data in summer, 1999, it is likely that both the dry deposition fluxes and ambient particulate PCBs concentrations were not site-specific.

• Asian Journal of Atmospheric Environment
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• 제11권3호
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• pp.202-216
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• 2017

Nitrogen (N) is an essential macronutrient. Thus, evaluating its flows and stocks in rice paddy ecosystems provides important insights into the sustainability and environmental loads of rice production. Among the N sources of paddy fields, atmospheric deposition and irrigation inputs remain poorly understood. In particular, insufficient information is available for atmosphere-rice paddy exchange of gaseous and particulate reactive N (Nr, all N species other than molecular N) which represents the net input or output through dry deposition and emission. In this study, we assessed the N inputs via atmospheric deposition and irrigation to a Japanese rice paddy area by weekly monitoring for 2 years with special emphasis on gas and particle exchange. The rice paddy during the cropping season acted as a net emitter of ammonia ($NH_3$) to the atmosphere regardless of the N fertilizer applications, which reduced the effects of dry deposition to the N input. Dry N deposition was quantitatively similar to wet N deposition, when subtracting the rice paddy $NH_3$ emissions from N exchange. The annual N inputs to the rice paddy were 3.2 to $3.6\;kg\;N\;ha^{-1}\;yr^{-1}$ for exchange, 8.1 to $9.8\;kg\;N\;ha^{-1}\;yr^{-1}$ for wet deposition, and 11.1 to $14.5\;kg\;N\;ha^{-1}\;yr^{-1}$ for irrigation. The total N input, 22.8 to $27.5\;kg\;N\;ha^{-1}\;yr^{-1}$, corresponded to 38% to 55% of the N fertilizer application rate and 53% to 67% of the brown rice N uptake. Monitoring of atmospheric deposition and irrigation as N sources for rice paddies will therefore be necessary for adequate N management.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제4권1호
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• pp.31-42
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• 2000

The dry deposition velocities and fluxes of air pollutants such as SO2(g), O3(g), HNO3(g), sub-micron particulates, NO3(s), and SO42-(s) were estimated according to local meteorological elements in the atmospheric boundary layer. The model used for these calculations was the multiple layer resistance model developed by Hicks et al.1). The meteorological data were recorded on an hourly basis from July, 1990 to June, 1991 at the Austin Cary forest site, near Gainesville FL. Weekly integrated samples of ambient dry deposition species were collected at the site using triple-fiter packs. For the study period, the annual average dry deposition velocities at this site were estimated as 0.87$\pm$0.07 cm/s for SO2(g), 0.65$\pm$0.11 cm/s for O3(g), 1.20$\pm$0.14cm/s for HNO3(g), 0.0045$\pm$0.0006 cm/s for sub-micron particulates, and 0.089$\pm$0.014 cm/s for NO3-(s) and SO42-(s). The trends observed in the daily mean deposition velocities were largely seasonal, indicated by larger deposition velocities for the summer season and smaller deposition velocities for the winter season. The monthly and weekly averaged values for the deposition velocities did not show large differences over the year yet did show a tendency of increased deposition velocities in the summer and decreased values in the winter. The annual mean concentrations of the air pollutants obtained by the triple filter pack every 7 days were 3.63$\pm$1.92 $\mu\textrm{g}$/m3 for SO42-, 2.00$\pm$1.22 $\mu\textrm{g}$/m-3 for SO2, 1.30$\pm$0.59 $\mu\textrm{g}$/m-3 for HNO3, and 0.704$\pm$0.419 $\mu\textrm{g}$/m3 for NO3-, respectively. The air pollutant with the largest deposition flux was SO2 followed by HNO3, SO42-(S), and NO3-(S) in order of their magnitude. The sulfur dioxide and NO3- deposition fluxes were higher in the winter than in the summer, and the nitric acid and sulfate deposition fluxes were high during the spring and summer.

• Journal of Korean Society for Atmospheric Environment
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• 제18권E1호
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• pp.1-12
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• 2002

One technique for determining dry acid deposition fluxes involves measurement of time - averaged ambient concentrations of dry acid deposition species using filter packs (FP) coupled with estimates of mean deposition velocities for the exposure period. A critical problem associated with filter pack data comparisons between various field sampling networks is the use of diverse sampling flow rates and duration protocols. Field experiments were conducted to evaluate the effects of varying sampling flow rates, from 1.5 to 10 standard liters per minute, on total nitrate and sulfate measurements of specific dry acid deposition species . Collocated FP samplers were used to determine sampling and analysis data reproducibility and representativeness . Ambient air samples were simultaneously collected using groups of filter packs operated at various flow rates over identical 7 day periods. The species measured were sulfur dioxide, particulate sulfate , nitric acid and particulate nitrate. Statistical results (ANOVA; alpha level 5%) showed that neither the low nor high sampling flow rates caused a significant difference in the measurements of total sulfate and adjusted total nitrate (ATN) . However, it was concluded that for high flow rate sampling measurements, total nitrate (TN) could be affected during extended sampling durations because of potential nitric acid overloading and breakthrough. Although the previous workers (Costello, 1990; Quillian, 1990) used much higher sampling flow rates (~ 17 sLpm) than employed here, it was assumed that for a high loading (> 50$\mu\textrm{g}$ HNO$_3$) of nitric acid on the Nylon filters, a significant fraction (~10%) of nitric acid could pass through the Nylon filters and be collected on the carbonate impregnated filters. It was concluded that even at the highest sampling flow rate employed (10 sLpm) at the Cary Forest site, nitric acid breakthrough was less than 10% of the total HNO$_3$ collected. However, for a heavily polluted urban airshed or with longer sampling times , higher filter loadings could result in substantial nitric acid breakthrough and HNO$_3$concentrations would be underestimated.

• 환경영향평가
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• 제8권2호
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• pp.31-44
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• 1999

Atmospheric dry deposition flux and ambient particle mass size distribution were measured to evaluate the impact of atmospheric deposition around the Nanjido landfill sites. Wind direction affects greatly on the variation of mass flux and mass size distribution and made two times higher when the wind was blown from the road side. The effect of Nanjido landfill on the mass size distribution was significant comparing to simultaneously measured mass size distribution at the other sampling site. The results showed that the particle diameter bigger than $10{\mu}m$ explained the majority of atmospheric dry deposition flux. A survey was also carried out to investigate the contamination of soils in a completed Nanjido landfill. The chemical properties of the soil analyzed in the present study include pH, oxidation-reduction potential (ORP), anion and cation concentration, total organic carbon(TOC), and some-metal elements concentrations were analyzed. Microbial activity in the soils was also evaluated by measuring dehydrogenase activities. TOC in the soil contaminated with leachate was $467.0{\mu}g/g-dry$ soil, and the TOC in the soil, where Nanjido landfill gases were emitted from, was $675{\mu}g/g-dry$ soil. The highest microbial activity of $968.0{\sim}2147{\mu}g-TPF/g-dry$ soil day was found in the soil spouting Nanjido landfill gases. Compared with those in the uncontaminated soil, the concentrations of Cr, Cu and Ph in the contaminated soil were higher.

• 대한환경공학회지
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• 제22권3호
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• pp.575-585
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• 2000

서울지역의 질량 및 중금속 건식침적량과 대기중 입자의 입경분포를 1998년 7월부터 11월까지 건식침적판, 다단계 관성충돌 채취기(Cascade Impactor) 및 조대업자 채취기(Coarse Particle Sampler)를 사용하여 측정하였다. 인위적 오염원에 기인한 중금속(Cu, Mn, Ni, Pt, Zn)의 건식침적량이 주로 자연적 오염원에 기인한 중금속(Al, Ca)의 건식침적량에 비하여 약 10배에서 100배 정도 낮은 값을 나타내었다. 완전한 총 입자 및 중금속 입자의 입경분포는 입자 입경이 $10{\mu}m$보다 작은 영역에서 두 개의 peak를 보이고 $10{\mu}m$보다 큰 입자 영역에서 또다른 peak을 보이는 삼봉형(trimodal) 입경분포를 보여주었다. Sehmel-Hodgson 모델을 사용하여 건식침적속도를 추정하고 이를 이용하여 총 입자 및 중금속 입자의 건식침적량을 계산하기 위하여 다단계 모델(Multi-step model)을 사용하였다. 이 방법에 의하면, 건식침적량은 입자의 입경이 $10{\mu}m$보다 큰 입자들의 높은 건식침적속도에 의하여 크게 영향을 받고 이로부터 건식침적은 $10{\mu}m$보다 큰 입자들의 침적이 대부분을 차지한다는 것을 보여주었다. 측정된 입자의 입경분포와 추정된 건식침적속도를 이용하여 다단계 모델을 통하여 예측된 건식침적량은 직접 측정된 건식침적량과 비교하였을 때 잘 일치하였다.

• 한국대기환경학회지
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• 제19권5호
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• pp.583-594
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• 2003

Ozone is an important atmospheric pollutant that is occurred in tropospheric chemical process and it also affects the human health and plants. For a correct application of abatement strategies for ozone, it is necessary to understand the factors that control atmospheric ozone removal by dry deposition processes. The present study investigates the numerical simulation of the dry deposition velocity (V$^{d}$ ) obtained from PNU/DEM (Pusan National University Deposition Model). PNU/DEM includes seasonal categories, meteorological factors, surface properties and land-use types and proposes for an accurate numerical computation. And, this study examines the ability of the PNU/DEM to compute V$_{d}$ of ozone over water surfaces and evaluates PNU/DEM by comparing its estimated V$_{d}$ to past observed V$_{d}$ over water. The parametrization was found to yield V$_{d}$ values generally in good agreement with the observations for the deciduous forest and the coniferous forest. Ozone is removed slowly at wet surface or water due to its low water solubility. Therefore V$_{d}$ values over water were lower than Vd values over the other surfaces. Comparison of PNU/DEM simulated V d values to observations of ozone V$_{d}$ that have been reported in the literature implies that PNU/DEM produces realistic results.