It is well known that smoking generates harmful air pollutants. With smoking in buildings as well as in the streets prohibited, the need for smoking rooms has emerged. In this study, particle and CO contamination in a 63.6 m3 smoking room was experimentally investigated using Korean tobacco. Tobacco smoking was artificially simulated using a smoking machine. The number and size distribution of particles ranging from 10-420 nm and 0.25-32 μm were measured using a Nanoscan (TSI model 3910) and a portable aerosol spectrometer (Grimm model 1.109), respectively. CO concentration was also monitored using an IAQ monitor (Graywolf IAQ-Xtra 610). Four tobaccos were simultaneously smoked in each experiment, and the experiment was repeated four times. Maximum CO concentrations of 7-10 ppm were observed and high concentrations of particles (176,000-1,115,000 particles/cm3 for 10-420 nm, 3,700-5,200 particles/cm3 for 0.25-32 μm) were also monitored. The dominant size of tobacco particles was about 100 nm in diameter.
The present study investigated the concentration of gaseous odor emitted from paint manufacturing facilities and the cases of improvement for odor emission reduction. It was found that the companies located in odor management district observed the odor emission standard more than the companies located in other local industrial complex. We ascribed the reason to the continuous crackdown by local government and voluntary efforts of each companies. Finally, we described the improvement cases of process for odor emission reduction.
Odorous pollutants emitted from the manufacturing process of TFT-LCD were investigated to prepare the odor control plan. Odor measurements in the workplace of clean room were also carried out. The odorous pollutants detected in the organic and acid gas emission duct were acetone, acetic acid, IPA, nbutylacetate, PGMEA, cyclohexane, which were chemicals used for LCD manufacturing. Especially, acetic acid was turned out to one of the major odor substances in the acid gas emission duct because of its low odor threshold value. No odorous pollutants were detected in the toxic gas emission duct. Some organic gases detected in the clean room were due to the leakage from chemical containers or LCD devices.
현재 전세계는 재난으로 인한 국가 경제ㆍ사회전반에 막대한 영향을 미치고 있어 인증을 통하여 문화 확산과 더불어 표준 도입으로 재난의 선진관리체계의 확립이 요구되고 있다. 우리나라뿐만 아니라 국외에서도 방재관련 인증제도는 방재기술지정, 방재신기술검증 등 범용적이지 못하여 한계가 있으며, 일부하고 있는 방재기술에 대한 성능인증 범위를 현재의 기술인증에 국한하고 있고, 시스템 인증은 하고 있지 않고 있어, 이를 확대하여 국제적 흐름에 선제적 대응 필요성이 있다. 그러나 현재까지 우리나라는 방재기술은 주로 자연재해에 관련된 분야로 독자적 영역에서 관련기술들이 발전해 왔음. 최근의 동향을 보면 다양한 분야의 복합적 기술들의 융합을 통한 기술이 개발되고 있다. 따라서 국제표준화에 목표를 두고 개발하여 세계 시장을 리드하는 방재기술의 중심국가로 도약 하는 기술적 우위가 필요하다. 그러기위해선 국내의 방재기술인증 실태와 국외의 선진국에서 실행되고 있는 인증에 대한 비교분석을 통하여 한국형 방재기술성능 인증 기술개발에 따른 발판을 마련하여 국제표준화 토대를 마련하고 방재기술 성능인증 세부기준에 따른 방재관리의 표준화로 시너지효과를 도출하고자한다.
Emission characteristics of gaseous odor compounds emitted from the charcoal manufacturing process were investigated, and evaluated the odor removal efficiency of odor control devices. It was found that the measured odor dilution ratio of emission gases ranged from 10,000 to 44,814, which exceed largely the emission standard in the stack. Methylmercaptan, trimethylamine, hydrogen sulfide, acetaldehyde were turned out as major odor compounds of the charcoal manufacturing process. It was revealed that the odor removal ratio of odor control devices were very low due to the its improper maintenance and wrong design.
The generation of TiO2 nanoparticles by a thermal decomposition of titanium tetraisopropoxide (TTIP) was carried out experimentally using a tubular electric furnace at various synthesis temperatures (700, 900, 1100 and 1300℃) and precursor heating temperatures (80, 95 and 110℃). Effects of degree of crystallinity, surface area and anatase mass fraction of those TiO2 nanoparticles on photocatalytic properties such as decomposition of methylene blue was investigated. Results show that the primary particle diameter obtained from thermal decomposition of TTIP was considerably smaller than the commercial photocatalyst (Degussa, P25). Also, those specific surface areas were more than 134.4 m2/g. Resultant TiO2 nanoparticles showed improved photocatalytic activity compared with Deggusa P25. This is contributed to the higher degree of crystallinity, surface area and anatase mass fraction of TiO2 nanoparticles compared with P25.
In this study, the fundamental experiments were performed for catalytic oxidation of NO (50 ppm) on MnO2 in the presence of ozone. The experiments were carried out at various catalytic temperatures (30-120℃) and ozone concentrations (50-150 ppm) to investigate the behavior of NO oxidation. The honeycomb type MnO2 catalyst was rectangular with a cell density of 300 cells per squuare inch. Due to O3 injection, NO reacted with O3 to form NO2, which was adsorbed at the MnO2 surface. The excessive ozone was decomposed to O* onto the MnO2 catalyst bed, and then that O* was reacted with NO2 to form NO3-. It was found that the optimal O3/NO ratio for catalytic oxidation of NO on MnO2 was 2.0, and the NO removal efficiency on MnO2 was 83% at 30℃. As a result, NO was converted mainly to NO3-.
This study examined the catalytic destruction of 1,2-dichlorobenzene on V2O5/TiO2 nanoparticles. The V2O5/TiO2 nanoparticles were synthesized by the thermal decomposition of vanadium oxytripropoxide and titanium. The effects of the synthesis conditions, such as the synthesis temperature and precursor heating temperature, were investigated. The specific surface areas of V2O5/TiO2 nanoparticles increased with increasing synthesis temperature and decreasing precursor heating temperature. In addition, the removal efficiency of 1,2-dichlorobenzene was promoted by a decrease in heating temperature. However, the removal efficiency of 1, 2-dichlorobenzene was decreased by an anatase to rutile phase transformation at temperatures 1,300℃.
The photodegradation and by-products of the gaseous toluene with TiO2 (P25) and short-wavelength UV (UV254+185nm) radiation were studied. The toluene was decomposed and mineralized efficiently owed to the synergistic effect of photochemical oxidation in the gas phase and photocatalytic oxidation on the TiO2 surface. The toluene by the UV254+185nm photoirradiated TiO2 were mainly mineralized CO2 and CO, but some water-soluble organic intermediates were also formed under severe reaction conditions. The ozone and secondary organic aerosol were produced as undesirable by-products. It was found that wet scrubber was useful as post-treatment to remove water-soluble organic intermediates. Excess ozone could be easily removed by means of a MnO2 ozone-decomposition catalyst. It was also observed that the MnO2 catalyst could decompose organic compounds by using oxygen reactive species formed in process of ozone decomposition.
Removal of elemental mercury (Hg0) with the reactive species produced from dielectric barrier discharge (DBD) was studied. We investigated the effect of operating parameters such as the applied voltage, residence time, initial concentration and co-existence of other pollutants. The removal of Hg0 was significantly promoted by an increase in the applied voltage of the DBD reactor system. It is important to note that at the same input power, the removal efficiency of Hg0 was much higher than that of NO gas. These results imply that if the DBD system is used as a NOx treatment facility, it is capable of removing Hg0 simultaneously with NOx.