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.

Complaints about foul odors are emerging as an issue, and the number of complaints is steadily increasing every year. Biofiltration is known to remove harmful or odorous substances from the atmosphere by using microorganisms, and full-scale biofilters are being installed and operated in various environmental and industrial facilities. In this study, the current status and actual odor removal efficiency of full-scale biofilters installed in publicly owned treatment facilities such as sewage, manure, and livestock manure treatment plants were investigated. In addition, the effects of design and operating factors on their efficiency were also examined. As a result, it was found that odor prevention facilities with less than 30% odor removal efficiency based on complex odors accounted for 40%-50% of the biofilters investigated. In investigating the appropriate level of operating factors on odor removal efficiency, it was found that compliance with the recommended values p lays a significant role in improving odor removal efficiency. In the canonical correlation analysis for the on-site biofilter operation and design data, residence time and humidity were found to be the most critical factors. The on-site biofilter operation and design data were analyzed through canonical correlation analysis, and the residence time and humidity maintenance were found to be the most important factors in the design and operations of the biofilter. Based on these results, it is necessary to improve the odor removal efficiency of on-site biofilters by reviewing the effectiveness of the operation factors, improving devices, and adjusting operating methods.

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.

We used three gas sensors to monitor hydrogen sulfide, ammonia, and volatile organic compounds (VOCs), which were frequently emitted from environmental facilities, such as municipal wastewater treatment, livestock manure treatment, and food waste composting facilities. Two electrochemical (EC) sensors for detecting hydrogen sulfide and ammonia, and a photoionization detector (PID) sensor for detecting VOCs were characterized in this study. The performance of their linearity by concentration levels, lower detection limit (LDL), repeatability, reproducibility, precision, and response time were tested under the laboratory condition. The linearity according to concentration levels were favorable for all three sensors with high correlation coefficients (R2 > 0.98). The ammonia sensor showed the highest LDL (18.6 ppb) and the hydrogen sulfide and VOC sensors showed 22.3 ppb and 26.7 ppb of LDL, respectively. The reproducibility and precision were favorable for all three sensors, indicating a lower relative standard deviation (RSD) than 0.9% in the reproducibility test and 7.2% in the precision test. The response times to reach target concentration were varied from 1 to 12 minutes. The ammonia sensor needed 12 minutes of response time at 1 ppm target the NH3 concentration and the hydrogen sulfide and VOC sensors needed less than 2 minutes of response time.

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.

In this study, the odor generated in a livestock farm with 500 heads of finisher breed in 661 m² was monitored during 6 months using a gas sensor, a wired / wireless communication system and database server. Odor unit, ammonia, hydrogen sulfide, and total volatile organic compounds (TVOC) were monitored using the gas sensor. To show the tendency of odorous substances generation, the odor concentration was shown in the graph on a monthly and daily basis. Among the analysis items, the maximum generation of odor was found to be closely related to the generation of hydrogen sulfide. Through observing the daily and monthly trends of odor substances, it was found that each substance was a useful indicator for monitoring odor, because ammonia, hydrogen sulfide, odor and TVOC were increased and decreased in a similar pattern. The odors were highest in the hours of the early morning (00:00-05:00), the evening (18:00-23:00), and the morning (06:00-11:00) in a day. After the use of the microbial agent was discontinued in autumn (October), anaerobic digestion of the manure in a pit proceeded and the amount of hydrogen sulfide increased. Therefore, despite a slight decrease in ammonia production, the odor unit level did not decrease after October but rather was somewhat increased. In the future, the use of the odor monitoring system is expected to improve the efficiency of odor sources management.

In order to reduce odor and methane emission from the landfill, open biocovers and a closed biofilter were applied to the landfill site. Three biocovers and the biofilter are suitable for relatively small-sized landfills with facilities that cannot resource methane into recovery due to small volumes of methane emission. Biocover-1 consists only of the soil of the landfill site while biocover-2 is mixed with the earthworm casts and artificial soil (perlite). The biofilter formed a bio-layer by adding mixed food waste compost as packing material of biocover-2. The removal efficiency decreased over time on biocover-1. However, biocover-2 and the biofilter showed stable odor removal efficiency. The rates of methane removal efficiency were in order of biofilter (94.9%)>, biocover-1(42.3%)>, and biocover-2 (37.0%). The methane removal efficiency over time in biocover-1 was gradually decreased. However, drastic efficiency decline was observed in biocover-2 due to the hardening process. As a result of overturning the surface soil where the hardening process was observed, methane removal efficiency increased again. The biofilter showed stable methane removal efficiency without degradation. The estimate methane oxidation rate in biocover- 1 was an average of 10.4%. Biocover-2 showed an efficiency of 46.3% after 25 days of forming biocover. However, due to hardening process efficiency dropped to 4.6%. After overturn of the surface soil, the rate subsequently increased to 17.9%, with an evaluated average of 12.5%.

The principal hygienic problem caused by livestock industry is the odor exposed to farm workers. This study was performed to assess air cleaner efficiency for reducing odor through on-site evaluation. The concentration of ammonia and hydrogen sulfide, which are major odorous compounds generated from livestock building, were monitored by realtime direct recorder. The odor mixture was measured by air dilution method applying human noses of five panels. Their reduction efficiencies were represented by difference between initial concentration exhausted by non-treatment and concentration measured after treatment of respective control mechanism (water, germicide and plasma ion) of air cleaner. Mean levels of ammonia and hydrogen sulfide were 1.84 (SD:0.22) ppm and 76.83 (SD:1.37) ppb for non-treatment, 1.23 (SD:0.09) ppm and 59.07 (SD:2.68) ppb for wet scrubber (water), 1.08 (SD:0.03) ppm and 58.55 (SD:1.62) ppb for wet scrubber (germicide), and 0.96 (SD:0.03) ppm and 53.66 (SD:1.37) ppb for plasma ion, respectively. Mean dilution factors of odor mixture were 100 for non-treatment, 66.9 for wet scrubber (water), 144.2 for wet scrubber (germicide), and 66.94 for plasma ion, respectively. Based on the results obtained from on-site evaluation, ammonia and hydrogen sulfide showed the mean reduction efficiency of 40% and 25.7% compared with non-treatment process of air cleaner, respectively. In the case of odor mixture, the highest dilution factor was observed at wet scrubber (germicide) compared with other control mechanism of air cleaner.

본 연구에서는 악취숙련도 시험을 위한 PTM 물질로 현장시료의 적용가능성을 평가하기 위하여 하수처리장에 채취한 현장시료의 안정성과 채취 균질성을 조사하였다. 또한 현장시료를 PTM으로 사용하여 71개 악취검사기관의 공기희석관능법의 숙련도 시험을 실시하였다. 다양한 설정값(참여기관 또는 기준기관의 악취지수 평균값이나 중위수)를 기준으로 3가지 Z-score 평가법(표준편차 이용한 Z-score, Robust 표준편차를 이용한 Z-score, 목표표준편차를 이용한 Z-score)으로 숙련도의 통계적 분석을 하였다. 하수처리장 농축조에서 채취한 현장시료는 2일 동안 희석배수의 변화 없이 안정적이었고, 참여기관을 4 그룹으로 나누어 순차적으로 채취한 현장시료가 균질한 것으로 평가되었다. 이는 현장악취시료가 악취 숙련도 평가를 위한 PTM 물질로 적용 가능함을 의미한다. 숙련도 시험결과의 통계적 분석을 통해 참여기관의 숙련도 만족비율은 Z-score 평가법이나 설정값의 기준(참여기관 또는 참고기관으로 선택한 3개 대학의 악취지수 평균값이나 중위수) 보다는 목표표준편차(S*ref)값에 의존하였다. 숙련도 만족비율은 S*ref 값이 증가함에 따라 증가하였으며, PTM 시료의 분석결과에 대한 변동계수(CV) 0.13에 해당하는 목표표준편차값에서 숙련도 만족비율은 약 93∼96% 수준이었다.

The purpose of this study is to investigate concentration and emission coefficients of 22 odorous compounds, which are regulated by the domestic act, emitted from pig buildings by on-site survey. The odorous compounds which were detected in at least one pig building were ammonia, hydrogen sulfide, methyl mercaptan, dimethyl sulfide, dimethyl disulfide, trimethyl amine, stylene, toluene, xylene and methyl ethyl ketone whereas other 12 odorous compounds were not detected in pig buildings. In general, indoor concentrations of odorous compounds in pig buildings were higher in scraper type than slurry type based on pig manure collection system and higher in enclosed type than winch-curtain type based on ventilation mode, respectively. In monthly distribution of odorous compounds, their concentrations in September and October when ventilation rate in pig building decreased relatively were generally higher than those in July and August when ventilation rate in pig building is relatively high. On the contrary, the emission coefficients of odorous compounds in pig building were generally higher in July and August than September and October. The levels of emission coefficients of odorous compounds obtained from this study were similar or slightly higher compared to those reported previously from foreign countries.

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.