해안지역 강수와 부유분진의 화학적 조성 비교

허철구,강창희 제주대학교 환경연구소 1994 환경연구논문집 : 제주대 Vol.2 No.1

This study was carried out to investigate the chemical composition of rainwater and atmospheric total suspended particulates (TSP) at coastal area. For this study, the rain-water and TSP were sampled a t Cheju-Kosan near the sea from May to December 1993, and then major water soluble ionic species(WSl) in those were analyzed. The concentrations of WSI in rainwater and TSP were lower than inland regions and had larger variation for each ion species. The sum of cation concentrations (166.4±336.7μeq/ℓ) were slightly greater than the sum of anion concentrations (163.2±249.5μeq/ℓ) in rainwater, but the sum of cation concentrations (0.157±0.056μeq/㎥) were considerably less than the sum of anion concentrations (0.188±0.0077μeq/㎥). The ion concentrations in rainwater were correlated negatively with precipitation, on the other hand those in TSP were correlated positively with wind velocity and had little correlation with precipitation. The ionic composition of rainwater, that is, Na^(-)>Mg^(2+)>Ca^(2+)>NH4_(4)^(-)>K^(+) for cation and Cl^(-)> S0_(4)^(2-)>NO_(3)^(-) for anion in order of abundance, showed different trend from the general trend in inland areas, however, that of TSP was similar to the general trend. The primary sources of Na^(+), Mg^(2+) and Cl^(-) were found to be seasalt and SO_(4)^(2-) and NH_(4)^(+) probably originated mainly from soil dust, while NO_(3)^(-) was possibly derived from various origins. And the contribution of seasalt to WSI in rainwater and TSP were about 70% and 37%. respectively. In addition, the average washout factor by rain fall for WSI was evaluated to 1.019 and the wet deposition rate of WSI was estimated at 10.65 ton/㎢/year.

제주시 대기부유분진 중 수용성 이온성분의 입경별 분포특성

허철구,송정화,이기호 한국환경과학회 2004 한국환경과학회지 Vol.13 No.12

Atmospheric particulate matters were collected by 8-stage non viable cascade impactor from October 2002 to August at Jeju City. Eight water-soluble ionic components (Na^(+), NH₄^(+), K^(+), Ca^(2+), Mg^(2+), Cr^(-) NO₃^(-) and SO₄^(2-)) were analyzed by Ion Chromatography. The concentration of particulate matters and eight water-soluble ionic components were determined to investigate their size distributions. Particulate matters exhibited a tri-modal distribution with peak value around 0.9, 4.0㎛ and 9.5㎛. In summer, the last peak value was lower than other season values likely due to particulate matter scavenged by rain water. Four ionic components (Na^(+), Ca^(2+) Mg^(2+) and Cl^(-)) exhibited a bi-modal distribution in the coarse mode whereas three ionic components (NH₄^(+), K^(+) and SO₄^(2-)) in the fine mode, with maximum peak value around 0.9um. NO₃ was found in both the coarse and the fine mode. The enrichment factor (E.F.) of each ionic components was calculated. Based upon E.F., it is considered that Na^(+), Cr, and K^(+) in coarse paricle mode were delivered form oceanic source, but other components might have other source origins.

대기환경지수를 이용한 제주지역 대기질 평가에 관한 기초적 연구

허철구,이기호,박용이 제주대학교 환경연구소 1997 환경연구논문집 : 제주대 Vol.5 No.-

The assessment of the air quality of Cheju area was carried out by AI(Air Index) and AEI(Air Environment Index). The air quality data, which measured at two air pollution monitoring network(Idodong ; located at Cheju city, Yongsuri ; located at western coastal region of Cheju island), were used in this study. The average concentration of major air pollutants(SO_(2), NO_(2), CO, TSP(PM-10)) were very low, but the ozone(O_(3)) concentration remarkably high. The monthly A1 values at Idodong and at Yongsuri were 7.0 ± 1.8 and 4.7 ± 1.4, respectively, therefore the air quality was classified as 'Good' level. And the monthly AEI values at same regions were in the range of 16.9-20 and 20.1-28, respectively, so the air quality was classified as 'Moderate' level. We found that the same air quality data was assessed at different level according to estimating mothod by A1 or by AEI. It seemed that the modification of the subindex and/or standard level was necessary to estimate A1 and AEI practically. Also, it was found that the critical pollutant was ozone in estimating A1 and AEI at Cheju area. But it assumed the ozone at Cheju area was caused by natural sources but anthropogenic sources. Thus, it seemed that the local background level of air pollutants was considered in estimating AI and AEI.

제주도의 대기오염 현황 및 장래예측

허철구,이기호,강창희 제주대학교 환경연구소 1993 환경연구논문집 : 제주대 Vol.1 No.-

This study deals with the air pollution status, the characteristics of air pollution sources and the prediction of future air quality in Cheju. The present air quality is estimated very satisfactorily in comparison with the air quality standard. And the concentration of sulfur dioxide in ambient air has been increased little for the last five years. The primary major source of air pollution is transportation which include 57% of total emissions of air pollutants. Also. air pollution sources are rnaldistributed on the seashore, especially concentrated on Cheju city, The emission rate of air pollutants in Cheju is 43,766 ton/year. but emissions per uint area (24ton/year. ㎢) is of very small quantity in comparison with that of other region. On the other hand, the ambient air quality a t the year 2001 is predicted by Val-ley model is lower than the air quality standard, althought emission rate is increased due to increasing in air pollution sources.

제주시 지역 대기분진의 화학적 조성 연구

강창희,허철구 濟州大學校 基礎科學硏究所 1992 基礎科學硏究 Vol.5 No.1

The monitorings of airborne particulates were performed at three sites in Cheju Do, that is Cheju city, Kosan and Onpyung area. In order to evaluate the air pollution level, the collected airborne particulates were analyzed for some aquatic ions and metal components by ion chromatographic method and inductively coupled plasma spectrophotometry. From the results of chemical analysis, it was found that the atmosphere of Cheju city was a little bit more polluted than that of Kosan and Onpyung area. Especially for SO₄²-, NO₃-, Pb, Fe components, Cheju city showed higher concentrations than other two places. Whereas in comparison with Seoul and Pohang city, which are highly polutted places, Cheju city showed lower concentrations for the most components than those places, and especially much lower for SO₄²-, Pb, Fe components.

Holzworth 방식에 따른 제주시의 대기 혼잡고 산정

이기호,허철구 濟州大學校 海洋硏究所 2002 해양과환경연구소 연구논문집 Vol.26 No.-

Our previous study has indicated that the morning mixing heights are believed to be overestimated, so the application of an adjustment factor to account for the heat-island effects suggested by Holzworth to data obtained at Jeju region still contains uncertainties. Therefore, the efforts are made, more properly, to calculate the urban morning mixing heights of Jeju City. For this purpose, the mixing heights at Jeju City are estimated twice for each day of one-year records of upper air observation at Gosan and surface air observation at Jeju City, by using the Holzworth approach during one year from November 1997. On the basis of urban-rural differences of minimum surface temperatures, it can be shown that the adjustment factor of 1℃ insead of 5℃ suggested by Holzworth is more reliable to account for the heat-island effects on Jeju region.

수중의 Pyrene, Chrysene 및 Benzo[a]pyrene의 광분해(I)

김지용,허철구,이민규,감상규 한국환경과학회 2003 한국환경과학회지 Vol.12 No.3

The photodegradation of pyrene, chrysene and benzo[a]pyrene, that were similar in structure among polycyclic aromatic hydrocarbons (PAHs), were investigated in water irradiated with a low-pressure mercury lamp (wavelength of 253.7㎚ and UV output of 1.35×10^-3J/s). The effects of several factors (t-BuOH, HCO_3^- and pH) on photodegradation of above three PAHs were also examined. The photodegradation rates of PAHs decreased with increasing the concentration of t-BuOH, but decreased little with increasing the concentration of HCO_3^- under the concentrations used in this study. The photodegradation rates of PAHs decreased with increasing pH, but their change were greater in case of pH increase from acid to neutral and were little in case of pH increase from neutral to base. The photogradation rates of PAHs fitted a first-order kinetic model and their photogradation rates decreased in the following sequences: pyrene>chrysene>benzo[a]pyrene among the PAHs used.

천연 제올라이트에 의한 Phosphamidon 및 Fenitrothion의 흡착 특성

감상규,허철구 濟州大學校 海洋硏究所 2002 해양과환경연구소 연구논문집 Vol.26 No.-

The adsorption characteristics of phosphorus insecticides(phosphamidon and fenitrothion) used in large amounts in golf course in natural zeolite(clinoptilolite) was investigated. The distribution coefficient, K_D and Freundlich constant, K_F, were higher for fenitrothion than those for phosphamidon, i.e., fenitrothion with the higher octanol-water partition coefficient(K_OW) was adsorbed the more on natural zeolite. The pesticide amount per unit mass of natural zeolite, decreased with increasing temperature but independent of pH, regardless of pesticides used in this study.

폐기물 소각재의 매립처분시 중금속 용출특성

박용이,허철구,이기호 濟州大學校工科大學産業技術硏究所 1996 尖端技術硏究所論文集 Vol.7 No.2

This experimental study is carried out to estimate leaching characteristics of heavy metals in landfill of the ash from waste incinerator. The results obtained from this study are as follows. The leaching fractions of Zn, Cd, Fe and Ca are increased remarkably with increasing of the flow rate of influent water but the leaching fraction of Cu has quite small difference with flow rate. The leaching fractions of Zn, Cd, Cu and Ca are higher in early leaching period but the insoluble phenomena of these elements are turned up in later leaching terms. However the leaching fractions of Fe and Pb are almost constant from early leaching period to later leaching period. The cumulative leaching weights of heavy metals in condition of pH 3.7 of influent water are more than those in condition of pH 5.7. Also, the leaching rate of Cd, Ca and Zn are increased evidently only in initial leaching period, otherwise, those of Pb, Fe and Cu are increased continuously to the end in condition of pH 3.7. And the leaching weights of heavy metals from fly ash are relatively more than those from bottom ash but the those from mixed ash is similar to bottom ash. When soil layer is added to ash packed in column, the leaching weights of heavy metals from column are decreased remarkably as compared with those of only mixed ash packed.

제주도 연안해역을 중심으로 한 DMS 농도의 관측

강창희,허철구,이강웅,김기현 濟州大學校 基礎科學硏究所 1997 基礎科學硏究 Vol.10 No.1

The concentrations of dimethylsulfide (DMS) were determined using samples collected from a station located at Kosan, Cheju Island during two field campaigns held in December 1996 and January 1997. The atmospheric DMS concentrations measured at 6-hr intervals during the entire campaign periods, after excluding a few extreme values, spanned in the range of 14 to 410 pptv with mean and 1 SD value of 127±94 pptv (N=42). Between two month periods during which the field campaigns were conducted, a notable reduction in DMS levels was observed which was comparable to the dramatic shift in air temperature. A considerable difference was also noted in DMS levels, when data were grouped by day/night basis. The cause of unexpected, high day-to-night DMS ratios is best explained in terms of high efficiency of daytime source processes relative to low efficiency of nighttime sink processes due to the characteristics of the study location. The surface water DMS of the study site, although scarcely measure, also behaved similarly to its atmospheric counterpart with its range from 0.3 to 19 nM (N=11). When correlation analysis was conducted between the atmospheric DMS concentration and other concurrently determined parameters, significant correlations were observed from most basic meteorological parameters such as windspeed, relative humidy, and air temperature. However, the existence of "not-so-strong" correlations between air temperature and DMS concentrations relative to other ones indicated that the effect of temperature on DMS behavior must be reflected in more complicated manners at the study site. The sea-to-air flux of DMS was approximated through an application of the mass-balance flux calculation method of Wylie and de Mora(1996) under the assumption that sink mechanism within the marine boundary layer is in steady-state condition with its counterpart, source mechanism. Based on this estimation method, we reached a conclusion that oceanic DMS emitted from the southwest sea of the Korean Peninsula can amount to approximately 9~36GgSyr-1.