Desorption characteristics of waste activated carbons collected from chemicals manufacturing industries in Shiwha/Banwal industrial complex were investigated. Activated carbons were decomposed in a thermogravimetric analyzer (TGA) at 513K with heating rate of 10 ℃/min under nitrogen atmosphere. Activation energies and reaction orders for desorption, from the waste activated carbon were estimated by employing Friedman method and Freeman-Carroll method. It was found that the reaction orders of desorption in waste activated carbons were 0.27-1.69, and activation energies were 15.2-45.7 kJ/mol in Friedman method and 13.7-17.1 kJ/mol in Freeman-Carroll method.

The objective of this study was to estimate characteristics of the carbonyl compounds at electronic industrial complex including residential area in Gumi. Also, the spatial analysis was applied to estimate spatial distribution of carbonyl compounds in study area. A total of 196 samples were collected from March 2007 to December 2007 by 2,4-DNPH cartridge and 5 carbonyl compounds such as acetaldehyde, propionaldehyde, butyl aldehyde, iso-valeraldehyde, and n-valeraldehyde were analyzed by HPLC. In this study, acetaldehyde showed average concentration was highest among carbonyl compounds during the sampling period. Average concentrations of carbonyl compound were similar between industrial complex and residential area and/or industrial area showed slightly higher than residential area. The spatial distribution and regional sources of pollution of each compound estimated by IDW spatial analysis method for spatial interpolation. Also, this study suggests that it is necessary to estimate odor compounds and to identify sources and apportion the ambient odor in order to establish effective odor control strategies and manage odor problem in industrial complex area.

Five kinds of odorous aldehyde were investigated at industrial complex in Busan. Samples were collected by DNPH cartridge at 24 work places, 81 samples in 44 sites, and analysed by HPLC/UV system. Acetaldehyde was detected in 78 samples with range of 1.2~299.7 ppbv. Propionaldehyde, butyraldehyde, n-valeraldehyde and i-valeraldehyde were detected in 7 samples, 11 samples, 2 samples and 9 samples, respectively. Measured concentration of propionaldehyde, butyraldehyde, n-valeraldehyde and iso-valeraldehyde were ranged 14.8~74.1 ppbv, 1.6~132.0 ppbv, 11.7~13.3 ppbv and 113.9~8858.9 ppbv, respectively. Among total analysed samples, 15 samples were over than degree 3 of calculated odor intensity. All of i- Valeraldehyde detected samples were showed over than degree 3. The work places subsisted aldehydes with high concentrations were related with leather-factory wastes disposal plant, leather, feedstuff, producing synthetic seasoning and textile mill.

Absorption characteristics of formaldehyde (one of odors) were investigated using a bubble tank. The capacity of reaction tank made of acrylic is I liter and the experiment was carried out as semi-batch mode (for given absorbent packing, formaldehyde was fed continuously with flow rate of 2 liter/min). As operating variables of experiment, concentration of formaldehyde (400~800 ppm), absorption temperature (25~45℃), and packing volume of absorbent (100~300 mL) were used. The experimental results showed that the removal efficiency of formaldehyde decreased from 5 to 10% as the concentration of formaldehyde and the absorption temperature increased from 400 to 800 ppm, and from 5 to 10%, respectively, while it increased with the increase of the packing volume of absorbent.

Silver nano-particles, that were either attached on granular activated carbon or dispersed in a liquid solution, were applied to investigate the removal efficiency of airborne bacteria. The antibacterial experiments were performed by changing the gas residence time in a GAC filtration column and a scrubber module. The GAC filter experiment showed that the antibacterial efficiency declined with time at a gas residence time (RT) of 0.02 second, and the bacterial quantity in the outlet of the column exceeded that of the inlet after 30 hours of operation. However, when using Ag-GAC, the removal efficiency was higher than that of the GAC, and it was maintained over a 3-day period. The experiment results at different gas RTs of 3, 1.5 and 0.5 seconds also showed that Ag-GAC had higher antibacterial efficiencies. The low antibacterial efficiency at a short RT indicates that a careful consideration needs to be implemented for the design of indoor air purification devises. In the scrubber experiment using distilled water, a removal efficiency of 50% was observed initially; however, it declined gradually and the outlet bacterial quantity was even higher than that of the inlet. This result was mainly due to the accumulation of bacteria in the recirculating solution. Contrarily, another scrubber experiment using silver nano-particle solution showed that an antibacterial efficiency of 66% was maintained over a 3-day period. Silver nano-particles were able to minimize the growth of microorganisms in the spray solution, and it resulted in an improved and stable efficiency for the airborne bacterial control.

This study aims to understand the correlation between odor intensity and dilution factor using the Air Dilution Olfactory Method, which is suggested in the Standard method of Odor Compounds, by measuring odor intensity and dilution factor for 4 types of sulfur compounds. For the measurement, 13 panel members were selected through a panel test, and odor intensity and dilution factor by substance produced from the selected panel were estimated. The estimation showed that the correlation of odor intensity with dilution factor for the 4 sulfur compounds can be reasonably expressed by the equation [I = AㆍLog D+0.5]. The result of this study is suggested to be used as a base data for research on measures to improve the regulation standards for complex odor concentration at a boundary site in operation, as well as a correlation between odor intensity, concentration and dilution factor for the designated odor substances, and their characteristics.

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.