Adsorption technology can effectively handle the volatile organic compounds (VOCs) from waste gas. However the adsorption of VOCs at elevated temperature (>30oC) and high humidity conditions results in competitive adsorption between VOCs and the moisture. Furthermore, physical adsorption at an elevated temperature is the cause of degradation in the regeneration process performance. In this study, toluene as waste organic solvent in air at elevated temperature and high humidity was used to measure performance. The effects of the SiO2/Al2O3 ratio of zeolites, the adsorbent material coated on adsorption regenerative rotors, on the adsorption performance of toluene with respect to temperature (30~50oC) and relative humidity (50~90%RH) have been investigated. The adsorption of toluene decreased as relative humidity and adsorption temperature rose. The result shows that Htype ZSM5 (SiO2/Al2O3=100) zeolite exhibited the highest adsorption capacity for toluene at elevated temperature and humidity conditions. The physical and chemical adsorption of toluene on acid sites of zeolite were confirmed by this study.

The correlation analysis between odor sensor and air dilution olfactometry method with odor emission facilities was performed for the real-time evaluation of odor emitted from the 13 facilities. The total correlation was less significant for all facilities due to various emission characteristics of odor. The correlation for the individual facility, however, showed a higher correlation coefficient (R=0.7371~0.9897). Especially, the strong correlation (above 0.9) was observed for the industry type with the odor characteristics like tobacco, styrofoam, acetic acid, and burning smell. The repeated odor measurements using the odor sensor showed good reproducibility with the mean relative standard deviation of 5.06%. The odor sensor could be useful tools for identifying and evaluating odor with an olfactometry in field, if the use and proofreading of the odor sensor are improved by a standardized method.

The aim of this study is to analyze error cases induced during the proficiency test of certified odor measurement agencies. In the case of the homogeneity test performed in three panel groups, the geometric mean dilution factor of the site boundary PTMs(proficiency testing materials) was 1.4 ± 0.2, 1.7 ± 0.2, 1.8 ± 0.1 and that of the outlet PTMs was 3.7 ± 0.2, 3.7 ± 0.3, 3.7 ± 0.3, respectively. In the case of the stability test for 72 h, the geometric mean dilution factor of the site boundary PTMs was 1.6 ± 0.1 and that of the outlet PTMs was 3.6 ± 0.1. Among error cases induced during the proficiency test of certified odor measurement agencies, the proportion of error cases was in the order of case II(discontinuance of estimation)(40.0%) > case I(error on estimation procedure by panelist)(33.3%) > case III(miswriting of estimation result)(13.3%) > case IV(miswriting of dilution factor) and V(writing of wrong estimation result)(6.7%). Therefore, it seems likely that additional education related to error cases II and I is required.

The object of this study is to investigate the relationship between the air dilution sensory test and the threshold odor number (TON) method for evaluating the odor of domestic wastewater, plating plant wastewater, food plant wastewater and lake water. The dilution factor of raw wastewater evaluated by the air dilution sensory test was in the order of food plant > plating plant > domestic > lake, and that evaluated by the threshold odor number method was in the order of food plant > domestic > plating plant > lake. The same results were obtained when the raw wastewater and lake water were diluted 2 and 5 times with pure water. The relative geometric standard deviation determined from the threshold values of each panel on the air dilution sensory test was much larger than that calculated from results derived from the threshold odor number method. The relative geometric standard deviation obtained from samples with a low dilution factor was greater. There was a very good linear correlation (correlation coefficient = 0.968~1.000) between the air dilution sensory test and the threshold odor number method. But, the reduction in odor intensity (the slopes of regression curves) by dilution was dependent on the types of the odor-emission sources.

In this study, the characteristics of panel members with various factors on the odor judgement using a air dilution olfactory method were investigated. The frequency distribution curves of Dev(D/Ttotal) and Dev(D/T₃) were found to be a normal distribution, but it appears that values around median on the distribution curve of Dev(D/T₃) were relatively sparse. Factors of outlier deviate from a confidence interval of 99% were found to be male ＜ female, smoker ＜ non-smoker, experience ＜ non-experience, and bad ＜ common state of health. Data obtained from female panel members appears high positive(+) deviation on the odor judgement.

Long-term passive diffusive samplers(PDS) have been used to measure NO2 and SO2 concentrations at 21 sampling sites in Daejeon, Korea during the period of January 2000 - December 2002. The spatial distributions of annual NO2 and SO2 concentrations were mapped. Average annual NO2 concentration over the sampling period was 28.5±12.5 ppb, ranging from 1.2 to 81.7 ppb. Average annual SO2 concentration over the sampling period was 7.7±4.8 ppb, ranging from 0.6 to 26.8 ppb. On average, NO2 concentration was approximately 5.8%(1.6 ppb) larger in 2002. SO2 concentration was decreased by 13%(1.1 ppb) during the sampling period. The seasonal variation of NO2 and SO2 concentration was observed with a tendency to be higher in fall and winter. NO2 and SO2 concentrations measured at different site types(patterns of land use) show significant difference. The observed difference in concentration was associated with difference in emissions of NO2 from motor vehicles and SO2 by non-traffic fuel consumption for heating.

The effects of noble gas (such as helium, neon, argon, krypton, and xenon) on the sonolytic decomposition of water and 2-methyl-2-propanol(t-butanol) with 200 kHz high power ultrasound were investigated. The physical properties of the noble gas have an effect on the formation rate of products (H2O2, H2, O2) and the decomposition rate on the sonolytic decomposition of water. The pyrolysis products, such as methane, ethane, ethylene, and acetylene are formed during the sonolytic decomposition of t-butanol. From the estimation of the ratio [C2H4 + C2H2] / [C2H6], the cavitation temperature would be varied by the used noble gas. In all cases for the sonolytic decomposition of water, t-butanol, and diethyl phthalate, the decomposition rates were xenon > krypton > argon > neon > helium with a significant difference and were closely correlated with the formation rate of OH radical and high temperature inside the cavitation bubble under each noble gas.

Precipitation samples were collected at sixteen sites in Northeast Asia from June 1995 to February 1997, and were analysed for the anions SO_4^2- NO_3^- and Cl^- and for the cations Na^+, NH_4^+, K^+, Mg^2+ and Ca^2+ in addition to pH and conductivity measurements. The quality assurance of chemical composition data was checked by considering the ion balance evaluating by │h│ value and the conductivity balance. The sum of cation concentrations were slightly greater than the sum of anion concentraions. For the anions, SO_4^2- clearly dominates in most of sampling sites whereas Cl^- is more abundant in coast and rural sites in Japan. For the cations, Ca^2+ and NH_4^+ are generally the more abundant ions except when sources of Na^+ exist. The contribution rate of nss-SO_4^2- and NO_3^- to acidity are about 70% and 10-30%, respectively. The neutralizing capacity by a major neutralizing cations such as NH_4^+ and nss-SO_4^2+ are above 98%(heavy polluted and urban sites in China), above 70%(urban sites in Japan and in Korea, coast sites in China) and above 60%(rural sites in Japan and in Korea), respectively.

The structure such as building and cultural properties was composed of various materials like wood, metal and stone that have been utilized and exposed to air, wind and rain for a long time. However, because of their special characteristics as structure, collecting of samples that may involve their destruction cannot be permitted, ever for material analysis. Therefore, in order to study the influence of atmospheric pollution on structure, atmospheric corrosion tests were achieved by making use of materials(bronze, ancient copper, copper, steel and marble) in field exposure tests. Atmospheric exposure sites are selected from places which are characterized by urban, rural, industrial and marine environments in Northeast Asia. According to the results of atmospheric corrosion tests; The corrosion rates of industrial sites in china were more serious than other sampling sites. In the correlation of meteorological factors, wet hours was defined as integrated hours under that atmospheric temperature is above O℃ and relative humidity in above 80% that has a great influence on corrosion tests of materials in case of a short time. The relative humidity was above about 75% that resulted in great increase of corrosion rates. In the esimation of corrosion rates between materials, corrosion rates of steel was about thirty times and decuple larger than that of other materials excluding marble in unshelterd exposure and in sheltered exposure.