We developed a wet scrubber by applying cyclone flow to the gas flow and using a spiral filter structure. While the size of a new scrubber was about half that of a conventional scrubber, the device showed relatively high efficiency in pollutants removal such as particulate matter and compounds inducing odor. The new scrubber installed in a plating industry showed a higher removal efficiency of about 5% for dust, about 23% for hydrogen chloride, and about 23% for sulfur dioxide compared to the conventional scrubber. Plurality of tubes in the spiral filer housing are arranged to be vertically shifted from each other. Because the upward residual gas does not directly rise vertically, the residence time of gas between the filter plates is extended. Thus, the purification efficiency of the pollutants was enhanced in the new scrubber. In addition, the new scrubber developed in this study is more cost effective because the cost saving in manufacturing it compared with a conventional scrubber increases with increasing the size of equipment. It is expected that a scrubber with better dust collecting efficiency can be obtained by carrying out a study in connection with facilities capable of controlling acidity of washing water.
Odor dispersion from road emissions were investigated using CFD (Computational Fluid Dynamics). The Shear Stress Transport k-ω model in FLUENT CFD code was used to simulate odor dispersion around the road. The two road configurations used in the study were at-grade and fill road. Experimental data from the wind tunnel obtained in a previous study was used to validate the numerical result of the road dispersion. Five validation metrics are used to obtain an overall and quantitative evaluation of the performance of Shear Stress Transport k-ω models: the fractional bias (FB), the geometric mean bias (MG), the normalized mean square error (NMSE), the geometric variance (VG), and the fraction of predictions within a factor of two of observations (FAC2). The results of the vertical concentration profile for neutral atmospheric show reasonable performance for all five metrics. Six atmospheric stability conditions were used to evaluate the stability effect of road emission dispersion. It was found that the stability category D case of at-grade decreased the non-dimensional surface odor concentration smaller 0.78~0.93 times than those of stability category A case, and that F case decreased 0.39~0.56 times smaller than those of stability category A case. It was also found that stability category D case of filled road decreased 0.84~0.92 times the non-dimensional surface odor concentration of category A case and stability category F case decreased 0.45~0.58 times compared with stability category A case.
The purpose of this study was to investigate the odor arising from the Cheong-ju industrial complex area for odor materials confirmation, and to predict the impact of the odor in the residential area using the CALPUFF Model. Among the odor causing substances in the area with a rising number of collective complaints due to odor, methyl sulfide, acetaldehyde, propionaldehyde, n-buthylaldehyde, n-valeraldehyde and styrene were detected. Odor causing substances detected in the area surrounding the industrial complex include ammonia, hydrogen sulfide, n-buthylaldehyde, toluene, xylene, benzene and styrene. Using the CALPUFF Model, it was predicted that 1hr average was 3.981~7.553 OU/m3 and 24hr average was 1.753~2.359 OU/m3. In terms of odor intensity, the predicted 1hr average was 0.6~0.9 and the 24hr average was 0.2~0.4.
Odor problems in urban areas have become a common cause of public complaints. In order to gain a better understanding of odor problems, we investigated the emission characteristics of odorants originating from manholes (n=22) and stormwater catch basins (n=48) (SCBs) around Wangsimni station in Seoul. To this end, concentrations of H2S and NH3 were measured after arbitrarily dividing the whole study area into five different districts. Our measurements were made to allow comparisons between three different criteria: (1) manholes vs. SCBs, (2) temporal variation between morning vs. afternoon, and (3) water content in the sewer system. The average concentration of H2S in manholes and SCB were 2.39 ppm and 0.81 ppm, respectively. In contrast, their NH3 counterparts were 1.86 ppm and 1.02 ppm, respectively. According to the contouring method made to identify spatial distribution characteristics, of odorants a relatively lowland site D was expected to work as a significant emission source in light of the transportation patterns of a sewer system. Moreover, higher concentrations of odorants were prevalent in the afternoon (as the prime time for commercial activities) relative to before noon. If concentration data are converted into odor intensity, H2S was the predominant component exerting controls on the odor pollution in these underground environments.