The air dilution olfactory method to measure complex odors needs to store and carry odor samples from the field sampling until the analysis in laboratories. Until the analysis of sample in the laboratory, odor dilution factor (odor sensitivity) in the sample bag may decrease over time depending on the characteristics of each odor substances. This is one of the limitation for the air dilution olfactory method. Thus, the air dilution device enable to measure without loss in complex odors of samples. Recently, many studies on the performance test of on-site air dilution devices, i.e., field olfactometer, has been conducted to figure out the feasibility of the field olfactometers. In this study, seven odor samples were collected from five odor emission source sites. And comparative analysis with the air dilution olfactory method was carried out to assess the field applicability of the olfactometer. As results, the performance of the field olfactometer used in this study is regared as the affordable method. The dilution factors from between two methods showed the similar values, indicating low values of standard deviations. In order to ensure the accuracy and precision of measurement data using the field olfactometer, methodology minimized variables (that may affect measurement) needs to establish.

The concentrations of volatile organic compounds (VOCs) and odor-inducing substances were measured using selected ion flow tube mass spectrometers (SIFT-MS) and a drone equipped with an air quality monitoring system. SIFT-MS can continuously measure the concentration of VOCs and odor-inducing substances in realtime without any pre-treating steps for the sample. The vehicle with SIFT-MS was used for real-time measurement of VOC concentration at the site boundaries of pollution sources. It is possible to directly analyze VOCs concentration generated at the outlets by capturing air from the pollution sources with a drone. VOCs concentrations of nine spots from Banwol National Industrial Complex were measured by a vehicle equipped with SIFT-MS and were compared with the background concentration measured inside the Metropolitan Air Quality Management Office. In three out of the nine spots, the concentration of toluene, xylene, hydrogen sulfide, and methyl ethyl ketone was shown to be much higher than the background concentration. The VOCs concentrations obtained using drones for high-concentration suspected areas showed similar tendencies as those measured using the vehicle with SIFTMS at the site boundary. We showed that if both the drone and real-time air quality monitoring equipment are used to measure VOCs concentration, it is possible to identify the pollutant sources at the industrial complex quickly and efficiently check sites with high concentrations of VOCs.

In this study, real-time monitoring of air quality using a real-time mobile monitoring system was conducted to identify the emission characteristics and current status of air pollutants and odorous substances that are mainly generated in domestic dyeing industrial areas and to trace the pollutant sources. The concentration of toluene in the industrial area was detected up to 926.4 ppb, which was 3 to 4 times higher than that of other industrial areas. The concentration of methylethylketone was 124.7 ppb and the concentration of dichloromethane was 129.5 ppb. Acrolein concentration was highest at E point at 521.6 ppb, methanol concentration was highest at D point at 208.8 ppb, and acetone concentration was highest at M and N points at 549.3 ppb. The most frequently detected concentration of pollutants in the air quality monitoring results in the industrial area was, in descending order, toluene > methanol > acrolein > dichloromethane > acetone, which was similar to the chemical emissions used in the industrial area by the Pollutant Release and Transfer Register data. The concentration of odorous substances measured in real time was compared with the concentration of minimum detection, and the concentration of hydrogen sulfide was about 10 times higher than the concentration of minimum detection at A point, which was judged to be the main odorous cause of A point. In the future, if the real-time mobile measurement system is constructed to automatically connect wind direction/wind speed, PRTR (Pollutant Release and Transfer Register) data and SEMS (Stack Emission Management System) data, etc., it was judged that more accurate monitoring could be performed.

In this study, the grid field olfactory odor method was supplemented to the domestic situation in the surrounding areas of a domestic science industrial complex. The actual condition of the occurrence of odor frequency in the field was then investigated over the first period of late spring to summer and the second period of autumn in 2017. The frequency of odor occurrence in the area around the science industrial complex was increased as odor discharge facilities in the nearby area were concentrated. The odor occurrence frequency of the total period was 0.09~0.28, that of the first period was 0.08~0.32, and that of the second period was 0.05~0.25. The odor occurrence frequency in summer was higher than in autumn. The frequency by which the measurement of odor occurrence by smell type was most dominant was mainly smell of chemicals, plastics, and livestock houses during the first period, and the smell of chemicals, burning gases, and plastics during the second period. And the frequency of each smell type was judged to be different according to season. The odor occurrence frequency was measured as higher than 0.15, which is the standard of Germany's odor frequency in an industrial area, and it was judged that measures for odor management in the region were necessary. Since most of the odor discharge facilities are non-continuous systems and the odor generation frequency is more important than the concentration of the minimum detection concentration, it was judged that the German grid method can reflect the odor occurrence characteristics of the odor complaints or receptors for a certain period of time compared to the domestic measurement method. In the future, it was judged that the field olfactory odor method would be able to replace the evaluation method of odor assessment in Korea with the survey method of odor assessment under actual conditions in areas where it is difficult to access the odor discharge source or the receptor where odor complaints occur.

This study was performed to evaluate the odor occurrence of offensive leather odor in a district in Gyeonggi-do, where Jeil industrial complex is located, and its residential district, by using olfactory field frequency measurement (Gird Method). In addition, we measured the composite odor. The target points were 9 spots in Jeil industrial complex and 12 spots in the residential district, and we conducted the measurements 13 times each spot. As a result, odor occurrence in descending order was investigated as follows, leather industry > drug industry > food industry. Moreover, odor exposure of the industrial complex exceeded the industrial zone standard of 0.15 (=German odor standard) in all 9 spots (average 0.78). In addition, odor exposure of the residential district exceeded the residential zone standard of 0.10 (=German odor standard) in 12 spots (average 0.78). All the composite odors were below 20 (industrial zone standard). However, as the odor intensity of the sampling site and the lab analysis data showed a large deviation, we found that much supplementation is needed of the odor analysis techniques in the equipment measurement methods.

Since the implementation of the Odor Prevention Act in 2005, the number of odor complaints has continuously increased due to the increased interest in the living environment. The current odor control means is a concentrationbased method for the source of odor. That is why there is a difference between the odor sensitivity and the result of the odor measurement in the odor damage area. The government is considering the introduction of the grid method, which is the odor management method of Germany, as the method of odor investigation in the odor damage area in the second comprehensive Odor Prevention Policy (2019-2028). The grid method is receptor-based odor measurement method that investigators use to judge odors in the field, task that expensive and requires substantial manpower and time. To study an odor measurement method that is suitable for domestic conditions, this study compared the correlation between results based on the odor frequency concept grid method around the livestock facilities and the result of ammonia concentration measured by passive air sampler. The correlation coefficient (R) that is between the frequency of odor per spot for the entire odor and the ammonia concentration that was measured by passive air sampler was 0.65 which is relatively good. Among the entire odor detected by the grid method, the correlation coefficient (R) between the odor frequency selected only for livestock odor and the ammonia concentration was significantly increased to 0.80. In addition, the correlation between odor exposure (ECPexist) and the ammonia concentration for the overall odor was 0.81 (linear) and 0.86 (index). If only the livestock odors were selected, the correlation between odor exposure and the ammonia concentration was very high at 0.96 (linear) and 0.95 (index).

In this study, we conducted a survey on odor characteristics of single odor and collective odor facilities using the German olfactory odor method and carried out the odor frequency modeling. The influence of the odor from a sewage treatment plant, which is a single discharge facility, was strong in the eastern and northern parts of the plant and appeared to be in good agreement with the areas where the odor complaints were frequent. The German olfactory method reflects the odor complaints and odor occurrence characteristics of the receptors as compared with the domestic odor measurement method. The influence of the odor from the odor control area, which is a collecting and discharging facility, showed a tendency in which the sum of the odor occurrence frequency increased with the proximity of the odor discharge facility to the dense industrial complex. Furthermore, it was judged that it is not easy to extract the odor frequency results for individual facilities because the survey subject is the group discharge facility area. Therefore, it will be necessary to introduce a method to manage odor in the future. In this study, the measurement of odor frequency using the German olfactory odor method is partially applied to some odor sources. Appropriately, it is not applicable to various emission sources. However, the odor measurement method based on odor occurrence frequency and odor sensory can be used for investigation of the actual condition, permits of odor discharge facilities and the environmental review.

The purpose of this study was to investigate the current status of odor and to examine the application method of the odor emission standard in a restaurant environment. The complex odor dilution concentrations (“times”) and odor compounds were measured in 8 restaurants. The highest complex odor dilution times were 966 in outlets and 97 in site boundaries of C restaurants. The average complex odor dilution times were 632 in outlets and 29 in site boundaries, which exceeded the allowable odor discharge standard of residential areas. Eighteen of the 22 specified offensive odor substances were detected. Aldehyde-type substances showed high concentrations, and the highest concentration of ethanol was detected in addition to the designated odorous substances. Dichloromethane, benzene, and phenol, which are harmful air pollutants, were also detected. The odorant concentrations of restaurants were found to exceed the odor standard threshold in A, B, and F restaurants. Upon review of the Japanese-style odor index respective to restaurant odor, it is difficult to apply an equivalent emission allowance standard as the permissible emission standard of the workplace. It is necessary to regulate emission standards by different emission standards. In the future, it will be necessary to determine how to measure the odor index and how to apply the odor emission standard to everyday facilities, such as restaurants, grocery stores, etc.

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 study analyzed performance assessment factors of odor sensors from 4 different manufacturers, including minimum detection limit, humidity stability and temperature stability. In the minimum detection limit assessment, only one electrochemical gas sensor was able to detect ammonia and hydrogen sulfide at the concentration of 5 ppb. The standard deviation ratio was over 10%, and it increased as humidity rose. The range of temperatures in which the electrochemical and photoionization gas sensors could function well was between 25oC and 40oC, and the sensor output values were unstable at low temperatures. Regarding the temperature stability of the metal oxide semiconductor sensor for measuring complex odors, the sensor output values dropped considerably to 0~10oC, and were similar to the concentrations of odor gases generated at 25oC. The results of the test of odor sensor outputs after temperature and humidity pre-treatment revealed that the respective stable output values at 50% humidity and 25oC were similar to the concentrations of manufactured odors. In terms of temperature and humidity stability of the NH3, H2S and Complex odor sensors, all target substances had stable output values at 25~40oC and 50~65% relative humidity, and unstable values at low temperatures and high humidity. Therefore, implementing pretreatment systems including temperature and humidity correction (25~40oC, 50~65% RH) is necessary for the stable use of odor sensors.

In this study, odor sensors were evaluated in two areas, which were reproducibility of measurements and linearity and correlation of results. The evaluation of linearity and correlation showed that the linearity of the measurement object substance at low, medium and high concentrations of all intervals, and correlation (R2) also appeared to be quite high, at 0.8 to 0.9. Specific performance evaluation results of ammonia, hydrogen sulfide, TVOC and complex odor sensor to the individual substances are somewhat different, but the result have able tendencies. All odor sensors showed detectable in all metrics at 5 ppb concentration in temperature 25oC, humidity 50%. However, there is needs to be determined that in many cases the standard deviation is 10% or more in 5 ppb, and reproducibility appears in the high concentration region with a standard deviation of less than 10%. Because complex odor sensor (MOS sensor) output value is relatively accurate concentration value for the odor and the reaction was stable, MOS sensor is to be considered methods for measuring the complex odor. Reactivity of ammonia, hydrogen sulfide and TVOC odor sensor to the concentration of individual odor substances stably displayed, but the reactivity of the mixture material showed the same trend, however, the hydrogen sulfide and TVOC sensor reactivity were unstable. There is thus a need to maintain the proper temperature and humidity environmental operating condition of odor sensors.

In this study, the experimental feasibility of alkali absorption method, recommended for the analysis of volatile fatty acids (VFA), was evaluated by considering the vaporization efficiency in relation to Henry’s law. Many experimental steps involved in the analysis such as absorption of VFA into the solution (as sorbent), extraction of absorbed VFA from solution, and SPME analysis of extracted vapor are all prone to biases. The extent of bias involved in the extraction stage is estimated under the simulated conditions of active purging at two temperature conditions of 25 and 90℃. The results of computation based on this simulated condition indicated that recovery rate of VFA from absorbed solution can be 1.1% and 30.2% after 1 hour of purging, respectively. As this low recovery rate is directly associated with low sensitivity and poor reproducibility, this official testing method is prone to various sources of experimental biases. Because of these limitations involved in VFA analysis, this official method cannot be used reliably to quantify the VFA in ambient air samples. Consequently, it is desirable to replace this method with the other verified method with more confidence such as the combined application of sorbent tube and thermal desorption.

MIt is important to estimate odor impact from the emission sources located in the industrial complex to near-by residential area. To understand modeling capacity in describing the odor dispersion, we examined an accuracy of odor modeling comparing with concentric measurements of sensory odors from the industrial complex. The odor measurements were carried out 6 times at 10 sites along the concentric circles and they were compared with odor modeling results using CALMET and CALPUFF. Although there are some discrepancies between the modeled and measured odor intensities, the model could depict key characteristics of odor dispersion patterns. The uncertainties in emission data and meteorology were main causes of the discrepancies. The odor modeling procedure developed in this study can be used in odor forecasting system and odor impact assessment. In order to improve the accuracy of odor modeling, the improvement of odor emission data and systematic monitoring of the odor using sensor network are necessary in future.

This study aims to produce the threshold values of 12 specified offensive odor substances based on the 3 point comparison method instead of the 2 point comparison method of ASTM or CEN. As a result, the threshold values of individual odor substances, including Methyl mercaptane, Hydrogen sulfide, Trimethylamine, and I-Valeraldehyde ranged between 0.0001∼0.001ppm, while the values of Styrene and Ammonia were relatively higher than of other substances at 1.8ppm and 0.04 ppm respectively. The threshold values of the 12 specified odor substances were compared in Korea and overseas, which showed that the characteristics of olfactory response varied by substance and nation. When it comes to acetaldehyde or hydrogen sulfide, western countries, including the United States, tended to quite insensible compared to Koreans. Japanese people were more sensitive in the 12 specified odor substances than Koreans in general, suggesting that it is not only because of its olfactory ability, but because of the calculation method that produces Japan‘s dilution threshold values approximately 1.5 times as high as Korea"s.

Odor intensities, odor concentrations and volatile amine compounds were investigated at the two piggeries in Korea and the one in Japan. It was confirmed that the piggery where odor control had been carried out intentionally showed the lower values of sensory measurement than those where the odor control had not been under consideration and also found that the concentrations of volatile amines in the odor-controlled piggery showed lower values rather than the uncontrolled. In this investigation, we conclude that the activities such as circulation of air in pig houses, spraying deodorants and feeding the additive that is effective for reducing malodors from piggery could decrease the odors and the concentrations of volatile amines that are the cause of offensive odors from piggery.

The continuous odor monitoring system has an important role of grasping odor of weak time zone, when is difficult in direct sampling, by measuring the odorous compounds continuously for 24 hrs a day. However, the operation of the continuous odor monitoring system do not mean only a great number of analysis data being producted continuously. But also, in order to obtain high quality data, the analyzer is maintained under the optimum conditions and suitable QA/QC is necessary. The analysis data could be used as an alternative for understanding odor characteristics, odor causes, and odor reduction plan, and thus they should have a role of explaining the affection area, tracking" odor in conjunction with the odor dispersion models. Since the designated odor components in Korea Odor Prevention Act cannot reflect on all types of odorous compounds, additional compounds causing the odor problem should be analyze to comprehensive monitoring.

This study was carried out to estimate the usefulness of metal oxide semiconductor(MOS) sensor as an odor measuring instrument. In this study, sensor output for 12 legal malodorous compounds was measured by two kinds of the marketed MOS sensor and was investigated the correlation coefficient between sensor output and odor indicators as like odor concentration, air dilution ratio. As a results, it was estimated that MOS sensor has a high use possibility as odor measuring device for the single compound analysis, as the correlation coefficient between sensor outputs and odor concentration, R2 appeared to 0.9 or more high.

The purpose of this research is to evaluate the odor exhaust characteristics of Sihwa and Banwol industrial complex during one year in 2007 by the automatic odor analyzer. As the continuous monitoring results on the 54 odor items, the highest average concentrations in two complexes were p-diethylbenzene, ammonia, toluene and methylethylketone. The items haven highest contribution rate in Sihwa and Banwol industrial complex were Dimethyl sulfide, i-Valerie acid, i-Valer aldehyde, Valerie acid, Trimethylamine and Etylmercaptan, Hydrogen sulfide, Dimethyl sulfide, Formaldehyde, Trimethylamine. When the odor concentrations converted into the total odor intensity, The percentages of hour data appeared over 3 degree of odor intensity were 0.5% (40 hr) in Sihwa station and 3.0% (210 hr) in Banwol station, respectively. Over 1 degree of odor intensity which is odor threshold value also were 68.3% in sihwa station and 82.5% in Banwol station, respectively. The highest monthly odor intensity was shown in January and February. Therefore, continuous monitoring system for odor compounds through the odor automatic station seems to be the most efficient method for investigating odor exhaust characteristics.

Analytical methods for odorous butanol compound were developed using canister sampling method and solid adsorbent sampling method. Stability of butanol gas component was evaluated for enhancing accuracy of measurement and to avoid a problem of its poor stability due to its polar character. Quality control method of the analysis was also examined. Gaseous standard gas containing BuOHl and MEK was prepared using canister for evaluation of stability and analytical linearity. BuOH showed a poor stability and poor linearity compared to MEK. However, when the same VOC standard was prepared using adsorbent tube, the stability and linearity of BuOH were much better compared to canister method. Therefore, sampling for the measurement of BuOH in air using adsorbent tube can give better result compared to canister method.

In this study, we attempt to analyze for 4 compounds (MEK, MIBK, n-Butyl acetate, i-Butyl alcohol) in ambient air using on-line thermal desorber (on-line TD) with gas chromatograph/flame ionization detector (GC/FID). These compounds will be regulated by KMOE (Korean ministry of environment) within 2010. We tested two different experimentation. First, we try to find the influence of Nafion dryer for the 4 compounds. Second, we want to know basic analytical characteristic of target compounds through the linearity, reproducibility, and minimum detection limit. According to this study, target compounds are removed in Nafion dryer more than 80 percent, respectively. So, we progressed next experimentation progressed without Nafion dryer using hydrophobic cold trap. Results for each compounds showed good linearity (r²＝0.99 upper) and good precision (RSD＝1 % below). In additional, we analyzed the ozone precusors standard gas (56 compounds) using the same method to see if there are any peaks to be overlapped in ambient air. These results showed that there is no peak overlapped. This means that analytical system of this study could be used on-line analytical system. Minimum detection limit (MDL) value for this system are less than minimum malodor threshold concentration.