• Korean Chemical Engineering Research
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• 제51권2호
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• pp.195-202
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• 2013

본 연구에서는 Titanium(IV) sulfate($Ti(SO_4)_2$)와 암모니아수로부터 수열합성법을 이용하여 비교적 낮은 합성온도($80{\sim}100^{\circ}C$)와 상압에서 소성과정을 거치지 않고 $TiO_2$ 분말을 제조하였고, $TiO_2$ 제조 시 반응온도, 반응물의 초기농도, 혼합용액의 pH와 같은 반응조건에 따른 $TiO_2$ 입자의 결정구조와 입자분포, 형상 등과 같은 물리적 특성을 고찰하였다. 제조한 시료는 UV 조사 하에 Brilliant Blue FCF(BB-FCF)의 광분해 실험을 실시하여 광분해 성능과 DRS 분석을 통해 광촉매 활성을 비교하였다. 제조한 시료의 물성은 XRD, SEM, PL, 입도분포 측정을 통하여 확인하였다. Titanium(IV) sulfate($Ti(SO_4)_2$)의 초기농도가 증가할수록 $TiO_2$의 평균 입자크기와 결정화도는 증가하였고 광촉매 활성은 감소하였다. 혼합용액의 pH가 높을수록 평균 입자크기는 감소하였고 광촉매 활성은 증가하였다. 반응온도가 높을수록 결정화도와 광촉매 활성은 증가하였다. 이상의 결과들로부터 $Ti(SO_4)_2$와 암모니아수를 이용한 비교적 낮은 합성온도와 상압에서의 수열합성법으로도 순수한 anatase 결정구조의 $TiO_2$가 제조됨을 확인할 수 있었다.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2004년도 추계학술대회 논문집
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• pp.256-257
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• 2004

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2009년도 추계학술대회 논문집
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• pp.456-457
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• 2009

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 1996년도 한국대기보전학회 추계학술대회 요지집
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• pp.30-31
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• 1996

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2010년도 춘계학술대회 논문집
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• pp.564-565
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• 2010

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2010년도 춘계학술대회 논문집
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• pp.371-372
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• 2010

• 한국환경과학회지
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• 제29권2호
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• pp.177-189
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• 2020

We analyzed the recent characteristics of Particulate Matter (PM) including PM₁₀ (PM with diameter of less than 10 ㎛) and PM_2.5 (PM with diameter of less than 2.5 ㎛) observed in Busan metropolitan area, and compared them with those measured in Seoul metropolitan area. This analysis includes the monthly, seasonal, and annual variations and differences, in emissions and chemical compositions observed in both Busan and Seoul areas. Synoptic meteorological conditions were investigated at the time when high PM concentrations occurred in each of the two areas. The results showed clearly decreasing trends of annual mean concentrations with strong seasonal variations: lower in summer and higher in winter in both areas. In comparison with Seoul, the seasonal variation in Busan demonstrated relatively lower, but showed greater summer fluctuations than in Seoul metropolitan area. This is implying the importance of secondary generation of PM in summer via active photochemical reaction in Busan area. In high concentration days, Busan's chemical composition of sulfate was higher than that of nitrate in summer, whereas nitrate was higher than sulfate in Seoul. The ratios of NO₃^- to SO₄^2-(N/S ratio) showed lower in Busan approximately by a factor of 1/2(half of N/S ratio) in Busan compared with that in Seoul. Others such as synoptic characteristics and emission differences were also discussed in this study.

• 한국대기환경학회지
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• 제19권4호
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• pp.347-361
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• 2003

Sulfur dioxide (SO$_2$), ozone, total suspended particulates (TSP) and PM$_{2.5}$ were measured at Deokjeok Island in the Yellow Sea during April 1999 to June 2000. Although the emission amount of air pollutants is quite low in this small island of 36 km$^2$ with 1.4 thousand inhabitants, there are pollutant sources such as an oil -firing power plant and a wharf for ferryboat. The island is also influenced from the emissions from the greater Seoul area in the east and from China in the west. In order to characterize the pollutant variations due to interactions between transport and local emissions. the correlation between variations of SO$_2$ and ozone was investigated. Mass and ion concentrations of TSP and PM$_{2.5}$ were examined on selected episode days of positive and negative correlations between the two gaseous species in spring and winter. The effects of transport were pronounced on the days of positive correlation in spring with higher concentrations of ozone and PM$_{2.5}$. TSP concentrations were also high on these days because of high wind speeds. On the days of negative correlation in spring, frequent fog associated with low wind speeds facilitated SO$_2$ oxidation and increased sulfate accompanied with decrease in nitrate in PM$_{2.5}$ and chloride in TSP. This latter phenomena was noticeable since it showed that chemical composition of fine particles could be significantly altered not only during the transport but also by local environment.ronment.

• 한국대기환경학회지
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• 제12권3호
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• pp.323-332
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• 1996

Precipitation samples were collected by the wet-only sampling method at Seoul from September 1993 to June 1995. Sample were analysed for the anions $(NO_3^-, NO_2^-, SO_4^{2-}, Cl^-, and F^-)$ and cations $(Na^+, K^+, Ca^{2+}, Mg^{2+}, and NH_4^+)$ in addition to pH and electric conductivity. In order to establish the chemical analysis data of high quality, the assurance checks for analytical data of precipitation were performed by considering the ion balance and by comparing the measured conductivity with the calculated conductivity. As we applied the various assurance checking methods by the ion balance used until recently to a data set measured in this study, the f value expressed as $\Sigma C/\Sigma A$ was found to be not appropriate for the data screening. Also, the scattering plot between cations and anions in each sample was found to show the general tendency of ion balance but was proved to not quantitate the standard of data screening at a data set of samples of various concentration levels. The h value defined as (A-C)/C for C $\geq$ A and (A-C)/A for C < A was used to check the ion balance. However, the standard of data screening by h value must very in response to total ion concentration of samples. In this study, the quality assurance of chemical analysis data was checked by considering both the ion balance of evaluating by h value and the conductivity balance. Further the quality control was achieved by these quality assurance methods. As the result, 67 samples among total 77 were obtained as valid. As the central tendency value for a statistical summary in the analytical parametr of samples, the volume-weighted mean value was found to represent more the general chemistry of precipitation rather than the arithmetic mean. The volume-weighted mean pH was 5.0 and 25% of samples was less than this mean. The concentrations of sufate and nitrate in precipitation were 90.4 ueq/L and 32.4 ueq/L which made up 59% and 21% of all anions. The raion of $SO_4^{2-}/(NO_3^- + NO_2^-)$ in precipitation was 2.7, which indicates that the contributions of $H_2SO_4$ and $HNO_3$ to the acidity of precipitation are 70% and 30%, respectively.

• 한국환경과학회지
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• 제22권9호
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• pp.1199-1211
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• 2013

Mobile sources produce a significant fraction of total anthropogenic emissions in Korea and have harmful effects on air quality. Mobile emissions are intrinsically difficult to estimate due to complicated road networks and variations of traffic volume with location and time. To measure traffic pollutants with high temporal and spatial resolution under real conditions a mobile laboratory was designed. The mobile laboratory provide concentrations of $SO_2$, CO, NO, $NO_2$ and location coordinate value. This approach allowed for pollutant level measurements on many roads within short periods of time. In this study, on-road concentrations of $SO_2$, CO, NO and $NO_2$ were measured using mobile platform measurement along the 25 main roads in Busan to estimate the average air pollution level in short time difference. The measurements were conducted on favorable meteorological days from 2010 to 2012 and the overall concentrations of $SO_2$, CO, NO and $NO_2$ were 0.006, 0.8, 0.182 and 0.055 ppm respectively. The result showed that the concentration of CO, NO and $NO_2$ on road were twice, 18 times and 2.5 times higher than regional air quality monitoring sites mean in same period.