This research determined the threshold value of 12 specified offensive odor substances based on the 3 point comparison sensory method. The panelist’s thresholds were calculated by taking the arithmetic, geometric mean, and 50th percentile. Three methods of calculating the odor thresholds from the same data are compared. For 12 odor substances, the panelist’s thresholds were showed logarithmically normal distribution. The 50th percentile was the best method among the three methods of caculating the odor threshold from the 72 panel’s thresholdes. As a result, the threshold values of individual odor substances, including methyl mercaptane, hydrogen sulfide, trimethylamine, and i-valeraldehyde ranged between 0.0001~0.001 ppm, while the values of styrene and ammonia were relatively higher than of other substances at 0.089 ppm and 3.2 ppm, respectively. The threshold values of the 12 specified odor substances were compared in Korea and overseas, which showed that the characteristics of sensory response varied by substance and nation.

This study aims to understand the correlation between odor intensity and dilution factor using the Air Dilution Olfactory Method, which is suggested in the Standard method of Odor Compounds, by measuring odor intensity and dilution factor for 5 types of carbonyl compounds. For the measurement, 13 panel members were selected through a panel test, and odor intensity and dilution factor by substance produced from the selected panel were estimated. The estimation showed that the correlation of odor intensity with dilution factor for the 5 carbonyl compounds can be reasonably expressed by the equation [I = AㆍLog D + 0.5]. The result of this study is suggested to be used as a base data for research on measures to improve the regulation standards for complex odor concentration at a boundary site in operation, as well as a correlation between odor intensity, concentration and dilution factor for the designated odor substances, and their characteristics.

This study aims to understand the correlation between odor intensity and dilution factor using the Air Dilution Olfactory Method, which is suggested in the Standard method of Odor Compounds, by measuring odor intensity and dilution factor for 4 types of sulfur compounds. For the measurement, 13 panel members were selected through a panel test, and odor intensity and dilution factor by substance produced from the selected panel were estimated. The estimation showed that the correlation of odor intensity with dilution factor for the 4 sulfur compounds can be reasonably expressed by the equation [I = AㆍLog D+0.5]. The result of this study is suggested to be used as a base data for research on measures to improve the regulation standards for complex odor concentration at a boundary site in operation, as well as a correlation between odor intensity, concentration and dilution factor for the designated odor substances, and their characteristics.

This study attempts to identify whether Phenethylamine (PTA), having a similar smell to fish malodor, is appropriate as a replacement of Trimethylamine (TMA). In a continuous measurement test, the odor intensity of both reagents TMA and PTA measured within 5 minutes showed between 0.4~0.7, indicating a dramatic reduction in olfactory sense, while the measurement test conducted after olfactory recovery did not represent much decrease. The result shows that both TMA and PTA have odors that stay long, but are judged to be inappropriate as a replacement as they stimulate the olfactory sense of the panel and give direct impact on the panel"s next judgement.

Odor management area was introduced by Odor prevention laws in 2004. Odor is generated a lot of sources. It is generated from various process as well as stack outlet. So it is hard to control odor. The ministry of environment develops the system to control odor. Nineteen areas were selected as Odor management area. Odor management area should be conducted for periodical research on the actual condition. Odor is normally measured by Odor analysis method. However, there are some difficulties to conduct by Odor management area because of measurement frequency, limitation of areas and high cost. Therefore we need to figure out how to reinforce this performance in Odor management area. So we have checked possibility of monitoring system with realtime odor monitoring, electron sensor, mobile communication and odor modeling system. The Odor monitoring system is consist of realtime monitoring system and electron sensor system. The Odor monitoring system could be checked for odor concentration and source of odor by accessing internet and mobile communication.

The ammonia in ambient were sampled by high efficiency diffusion scrubber (HEDS) and analyzed by IC. Ammonia showed high linearity (R²＞0.999) of the calibration curve and good repeatability (RSD＜5%). The detection limit of Ammonia was about 0.05 ppbv. Average concentration of Ammonia was 12.7 ppbv, Instantaneous maximum concentration was 83.4 ppbv. Continuous sampling method is proper to monitor ammonia which is the odor material instantaneously increased mainly affected by meteorological condition. The sampling and analysis process can be automated and performed in real-time by continuous sampling of HEDS-IC system.

The organic acids in ambient were sampled by high efficiency diffusion scrubber (HEDS) and analyzed by IC. Most of organic acids showed high linearity (r²＞0.999) of the calibration curve and good repeatability (RSD＜10%). The detection limit of organic acids was about 7 pptv. The concentration of acetic acid was ranged from 0.43~1.74 ppbv, formic acid was ranged from 0.28~1.85 ppbv. Since the organic acids are one of odor compound species with instant production characteristics and affected easily by weather, continuous analysis method is better than intermittent method to determine these compounds. The sampling and analysis process can be automated and performed in real-time by continuous sampling of HEDS and IC.

Experiments were conducted to analyze the concentration of sulfur compounds present in ambient air at the pg or ppt level. The compounds were estimated using GC/PFPD (Gas Chromatography with Pulsed Flame Photometric Detector) analyses with a Thermal Desorber (TD). The analytical results showed very stable and precise retention time values (RSD: ＜ 0.22%), peak area (RSD: ＜ 3.9); the coefficients of the calibration curves were also determined (r²: ＞ 0.991). Also, with respect to the recovery rates of the sulfur compounds from dry air, those for H₂S, MM, DMS and DMDS were 94, 100, 113 and 114%, respectively. In order to evaluate the sulfur chemicals in humid air, a study was conducted at RH of 55 and 100%. The recovery rate at a relative humidity of 55% was similar to that under dry conditions. However, recovery rates of H₂S and MM at RH 100% were reduced to 70 and 77%, respectively.

The standard emission rate(ERs) of isoprene was quantitatively measured in situ from Quercus mongolica Fischer that dominates more than about 85% of domestic oak trees. The ERs values in spring and summer were similar to 64.4 and 58.1 (㎍C/gdw/hr), respectively. The ERs in autumn, 7.06(㎍C/gdw/hr), was about 8～9 times lower than those in spring and summer. The coefficient of determination (r2) between ERs and CL․CT ranged from 0.593 to 0.836. The correlation coefficients between the ERs and PAR, the ER and temperature suggested that ERs have strong correlation with PAR(photosynthetically active radiation) and temperature. In addition, the high values of PAR, temperature, and ERs were found in the time zone of 15:00 ～17:00(spring), 15:00 ～ 16:00(summer), and 14:00 ～ 15:00(autumn).