In this study, the catalytic combustion of propionaldehyde, which is an Offensive Odorant Substance assigned by the Korean Ministry of Environment (KMOE), over alumina-supported manganese oxide (Mn/Al2 O3) catalysts was investigated. The combustion reaction was carried out in a fixed-bed reactor at the temperature range of 200 ∼340 ℃. Mn/Al2O3 catalysts with Mn loadings ranging from 3.9 to 18.3 wt.% were prepared by impregnation method. The physicochemical characteristics of the catalysts were analyzed by X-Ray Diffraction (XRD), Scanning Electronic Microscopy (SEM) and Brunauer-Emmett-Teller (BET). The Mn crystalline phases of the Mn/Al2O3 catalysts were identified as α-Mn2O3 and β-MnO2. Mn oxides were covered on γ-Al2O3 supports with an average diameter of around 1 μm. With the increase of Mn loadings, the BET surface areas, pore volumes and average pore diameters of the Mn/Al2O3 catalysts decreased. The catalytic activities of Mn/Al2O3 catalysts increased as the Mn loading was increased from 3.9 wt.% to 18.3 wt.%. The catalyst with 18.3 wt.% Mn loading was able to achieve 100% propionaldehyde conversion at 260 ℃. For the same temperature, a lower Gas Hourly Space Velocity (GHSV) and a lower propionaldehyde concentration promote the complete combustion of propionaldehyde.

The objectives of this study were to analyze the characteristics of odor in the major facilities of a fishery industrial complex using the air dilution olfactory method and the instrumental analysis method. The results indicate that although the limit of dilution to threshold (D/T) ratio in the major facilities is not regulated by the Odor Emission Standard, the mean (D/T) ratio over than 3,000 which is higher than the limit in the outlet of industrial area 3 times was found at three sampling sites. In the case of the concentration of the malodorous compounds, ammonia concentration is higher than any other odor compounds. The methyl mercaptan, n-Butyric acid and hydrogen sulfide as the main pollutants are confirmed by the odor quotient (OQ). In our study, it is showed a moderately good correlation between the (D/T) ratio and the sum of OQ. By this result, we can estimate the odor characteristics and evaluate the potential impact of each odor compound. In addition, we consider that it will affect the people"s normal life and even cause for complaint around the boundary area by the diffusion of odor.