the less-reported gaseous studies have primarily dealt with chemical process stream concentrations than indoor air quality (IAQ) concentration levels. Accordingly, the current study was conducted to establish the feasibility of applying visible-light-induced TiO₂ doped with sulfur (S) element to cleanse toluene and ehtyl benzene at IAQ levels. The S-doped TiO₂ was prepared by applying two popular processes and two well-known methods. For both target compounds, the two coating methods exhibited different photocatalytic oxidation (PCO) efficiency. Similarly, the two S-doping processes showed different PCO efficiency. These results indicate that the coating method and doping process are important parameters which can influence PCO efficiency. Meanwhile, it was found that the PCO efficiency of ethyl benzene was higher than that of toluene. In addition, the degradation efficiency of the target compounds increased as the relative humidity (RH) decreased. The PCO efficiency varied from 44% to 74% for toluene and from 68% to 95%, as the RH decreased. Consequently, it is suggested that with appropriate RH conditions, the visible-light-assisted photocatalytic systems can also become an important tool for improving IAQ.

The malodor control law enacted in 2005, regulated malodor substances ansmg from factory or service industry. In this work, an attempt is made to understand the actual conditions of malodor occurrence for types of industry and to settle trouble for a odor complaint. The odor concentration unit (o.u/㎥) of each major odor emitting industry was actualized by the indirect olfactory method including air dilution sensory test method in Korea. The industry that malodor complaint originate mainly were Chemical manufacturing industry, Waste disposal facilities and Livestock farming. As the results, Livestock farming were measured from 3 o.u/㎥ to 30 o.u/㎥ in the source boundary site, Waste disposal facilities were measured from 300 o.u/㎥ to 669 o.u/㎥ in the stack and Chemical manufacturing industry was analyzed from 300 o.u/㎥ to 1442 o.u/㎥ in the stack. Sampling of the source boundary site was demand the reform because malodor state at the field not expressed properly. In oder to solve such problem, propose total odor emission rate (T.O.E.R) introduction.

This study was performed to investigate the characteristics of indoor air quality (IAQ) in elementary and middle schools in Gyeongbuk area from July to November 2006 . The measurements of indoor air pollutants were made to cover such components as PM-10, CO2, CO, NO2, O3, HCHO, TVOC, TBC, and Radon from school classrooms. The results of this study can be summarized as follows: all of them were less than IAQ standards of Korea. The mean concentration were measured by 43.0 ㎍/㎥ (PM-10), 745 ppm (CO2), 56.1 ㎍/㎥ (HCHO), 350 CFU/㎥ (TBC), 0.026 ppm (O3), 0.6 ppm (CO), and 59.2 ㎍/㎥ (TVOC). Radon was not detected in all surveyed classrooms. The I/O ratio of PM-10 was 0.8∼1.4, while that for HCHO was 5.7∼9.0. Therefore, it was concluded that the indoor pollution of formaldehyde was very serious in classroom.

Present study evaluated the low-temperature destruction of n-hexane and benzene using mesh-type transition-metal platinum(Pt)/stainless steel(SS) catalyst. The parameters tested for the evaluation of catalytic destruction efficiencies of the two volatile organic compounds(VOC) included input concentration, reaction time, reaction temperature, and surface area of catalyst. It was found that the input concentration affected the destruction efficiencies of n-hexane and benzene, but that this input-concentration effect depended upon VOC type. The destruction efficiencies increased as the reaction time increased, but they were similar between two reaction times for benzene(50 and 60 sec), thereby suggesting that high temperatures are not always proper for thermal destruction of VOCs, when considering the destruction efficiency and operation costs of thermal catalytic system together. Similar to the effects of the input concentration on destruction efficiency of VOCs, the reaction temperature influenced the destruction efficiencies of n-hexane and benzene, but this temperature effect depended upon VOC type. As expected, the destruction efficiencies of n-hexane increased as the surface area of catalyst, but for benzene, the increase rate was not significant, thereby suggesting that similar to the effects of the reaction temperature on destruction efficiency of VOCs, high catalyst surface areas are not always proper for economical thermal destruction of VOCs. Depending upon the inlet concentrations and reaction temperatures, almost 100% of both n-hexane and benzene could be destructed. The current results also suggested that when applying the mesh type transition Metal Pt/SS catalyst for the better catalytic pyrolysis of VOC, VOC type should be considered, along with reaction temperature, surface area of catalyst, reaction time and input concentration.