C. obtusa, an essential oil produced in Jeollanamdo Gangjin, is the most effective plant oil for easing Sick House Syndrome, having an effect similar to a therapeutic walk in the woods and acting as a sterilizer. In light of its medicinal importance, its composition, antibacterial activity and ability to mitigate an offensive odor have been analyzed. Through GC-MS, I confirmed that it contains approximately 50 components, 80.30% of which are various monoterpenes. It was effective at alleviating malodors from formaldehyde, ammonia, trimetylamine and methylmercaptan as determined in colorimetric gas detection tube tests in comparison with lemongrass and clove leaf essential oil. I obtained from Minimal Inhibition Concentration(MIC) of C. obtusa, higher concentrations will lead to increased antibacterial activity. Therefore it is estimated that utility value of it will be grow more and more.
In this study, deodorizing efficiency of three deodorant products (1) A = ClO₂ Gel + charcoal, (2) B=Charcoal Gel, and (3) C = Gel (for Kimchi)) was investigated. For these experiments, a total of 15 odorants (4 reduced sulfur compounds, 2 volatile organic compounds, 7 carbonyl compounds, and 2 nitrogenous compounds) were investigated for a short term period. For the comparative analysis, 2 food types with strong odor properties (Kimchi and Fish) were selected and investigated. The analytical results were compared with respect to the blank sample (without deodorants) after normalization. Hence, if normalized concentration values are lower than unity one can assume that sample has positive deodorizing efficiency. The results of deodorant experiments indicate that the effects of the most common deodorant products are not effective enough to remove offensive odorants. However, the selection of deodorant products appears to be important, as they have very specific deodorizing efficiencies for certain compounds.
A three-dimensional Computational Fluid Dynamics (CFD) with the renormalization group (RNG) k-ε turbulence model was used to simulate flow patterns and corresponding dispersion of passive H₂S pollutant in urban area with complex terrains. The major emission sources of H₂S considered in this study include the sewage disposal plant and the leather waste water disposal plant located the northwest direction from the residential area. In order to describe the flow and dispersion characteristics of H₂S in the complex terrain, the terrain data in the modeling domain was processed as the input data for the CFD model, while the previous studies were conducted in flat terrains. The recirculating flow zone was formed behind the buildings, and the pollutant concentration in the zone was noticeably high because of limited ventilation. The velocity profile and ventilation rate along the height were calculated to identify the effective zone of weak flow and re-circulation by the buildings and complex terrains. According to this study, the CFD modeling was demonstrated to be highly effective to simulate the effect of buildings and complex terrains on the flow and dispersion of odors. Detailed studies are desirable to further validate the odor dispersion with measurements under more complex flow conditions.
In this paper the lifetime risk assessment of exposure to airborne volatile organic compounds (VOCs) in environmental atmosphere was carried out in one of the Korean industrial city, Gumi based on their measurements of VOCs at five representative outdoor monitoring sites. According to this study toluene, trichloroethylene, and dichloromethane are three main VOCs in Gumi. The carcinogenic risks 5the carcinogenic VOC are greater than the benchmark concentration (1.0E-6) in all five designated sites. Particularly, the Lifetime Cancer Risk in industrial complex 1 and 2 reached 9.64E-5 and 1.32E-4, respectively, both of which are far higher than the benchmark risks. The components of predominant risk in industrial areas are found as chloroform, benzene and trichloroethylene, while those of other sites are benzene and chloroform. It was estimated that the contributions of those componentsto cancer risk are not less than 90%. For non carcinogenic VOCs, the total hazard indices in 5 monitored sites are less than 1. The hazard index in industry complex No. 2 recorded the highest among 5 sites up to 0.663 due to the dominant contribution of 1, 2-dichloropropane by up to 50% (0.335). Based on this analysis, effective emission reduction for chloroform, benzene, trichloroethylene, and 1,2-dichloropropane will rapidly I the cancer risks and hazard indices in Gumi.
The malodor as the sense pollutions is rising to surface with a new environmental matter. Especially, malodor"s appeal is increasing steadily from a residential area of the industrial complex. The odor characteristic and odor active compounds of industries should be identified to solve this problem. The dye company was selected as a sample among the industries. Air samples of the dye company were sampled with polyester aluminum bag and it was analyzed by GC/FID/O and GC/MS. The feature of the complex odor was ironing, sour and burnt smell. The odor active compounds of individual odor which contribute these smell were mainly 2-ethyl-hexanal, octanal, 2-ethyl-1-hexanol and nonanal. This study will help odor problem of industries to solve effectively.
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.
This study aims to develop an odor intensity reference scale appropriate to the characteristics of Koreans, based on ASTM E544-99. The Odor Intensity Reference Scale of the United States utilized to make up for the absolute index of odor intensity. The concentrations of n-butanol, which is equivalent to the 5th stage of odor intensity in Korea, are proposed to be 100, 400, 1500, 7000, and 30000 ppm, respectively. Based on the ASTM E544-9 method, the reference scales of Korea odor intensity were compared and the result showed that the reproducibility and practicability of the method were satisfactory. it is therefore suggested that n-Butanol, which is processed with the proposed concentration levels as the absolute standards for odor intensity, can be used as Korea Odor Intensity Reference Scale for the experiment of panel screening test in an air dilution olfactory method.