Air quality monitoring data and meteorology data which had collected from 1995. 1. to 1999. 2. in six areas of Daegu, Manchondong, Bokhyundong, Deamyungdong, Samdukdong, Leehyundong and Nowondong, were investigated to determine the distribution and characteristic of ozone. A equation of multiple regression was suggested after time series analysis of contribution factor and meteorology factor were investigated during the day which had high concentration of ozone. The results show the following; First, 63.6% of high ozone concentration days, more than 60 ppb of ozone concentration, were in May, June and September. The percentage of each area showed that; Manchondong 14.4%, Bokhyundong 15.4%, Deamyungdong 15.6%, Samdukdong 15.6%, Leehyundong 17.3% and Nowondong 21.6%. Second, correlation coefficients of ozone, SO2, TSP, NO2 and CO showed negative relationship; the results were respectively -0.229, -0.074, -0.387, -0.190(p<0.01), and humidity were -0.677. but temperature, amount of radiation and wind speed had positive relationship; the results were respectively 0.515, 0.509, 0.400(p<0.01). Third, R2 of equation of multiple regression at each area showed that; Nowondong 45.4%, Lee hyundong 77.9%, Samdukdong 69.9%, Daemyungdong 78.8%, Manchondong 88.6%, Bokhyundong 77.6%. Including 1 hour prior ozone concentration, R2 of each area was significantly increased; Nowondong 75.2%, Leehyundong 89.3%, Samdukdong 86.4%, Daemyungdong 88.6%, Manchondong 88.6%, Bokhyundong 88.0%. Using equation of multiple regression, There were some different R2 between predicted value and observed value; Nowondong 48%, Leehyundong 77.5%, Samdukdong 58%, Daemyungdong 73.4%, Manchondong 77.7%, Bokhyundong 75.1%. R2 of model including 1 hour prior ozone concentration was higher than equation of current day; Nowondong 82.5%, Leehyundong 88.3%, Samdukdong 80.7%, Daemyungdong 82.4%, Manchondong 87.6%, Bokhyundong 88.5%.

The absorption of benzene in nonpolar solution was studied in a laboratory-scale of bubble column varying of gas flow rates and gas-to-liquid ratios. A bubble column had a 0.8～1×10-3 m3 total volume (height 1500 mm, diameter 50 mm). Solution analysis was performed by GC-FID and GC-MSD. The objectives of this research were to select the best absorption fluid and to evaluate the mass transfer characteristics under specific conditions of each absorption. The results of this research were follow as: First, the heat transfer fluid is more efficient than the other nonpolar solution in removing VOC. Second, The benzene removal efficiency improved according to an increasing rate of gas flow. Also, volumetric mass transfer rate of column can be enhanced by increasing gas flow rate. Finally, the relation of gas flow rates, liquid amount, and volumetric mass transfer coefficient was obtained as follows. Kya=0.5906(Vg/L)0.7611 The following correlation of mass transfer coefficient and efficiency was proposed. η=0.06078 Kya0.2444

The oil crisis of the 1970s and the rise in oil prices motivated people to implement energy conservation strategies. Buildings were fitted with additional insulation and reduced ventilation rates. The reduction of mechanical and natural ventilation rate led to increases in indoor pollutant concentrations which resulted in increased health risks from indoor exposure to pollutants. The variable-air-volume/bypass filtration system(VAV/BPFS) is a variation of the conventional VAV systems, The VAV/BPFS is an electronically controlled system that provides cost-effective thermal comfort and acceptable indoor air quality. Under controlled conditions in a chamber, a series experiments were performed to compare the ability of a VAV/BPFS to remove indoor aerosol concentration and to reduce energy consumption with that ability of conventional VAV system. Results show that the VAV/BPFS increases the effective ventilation rate and removes indoor air pollutant, and maintains acceptable indoor air quality without sacrificing energy consumption.