The PC game rooms in Korea have a problem in the aspect of indoor air quality because there are many occupants for 24 hours where the smoking is allowed. This study was carried out to evaluate indoor air quality (IAQ) including the size distribution of respirable suspended particulates (RSP) and airborne nicotine concentration in selected PC game rooms. The subjects are 6 PC game rooms in Seoul and Sung-Nam Cities. In this study, airborne RSP and nicotine concentrations were measured during a period from February to March, 2003. Significant correlation has been found between the concentrations of RSP and nicotine in PC game room. Also the negative correlation was found between room area and number of operating fan. The correlation coefficients between RSP size distribution and nicotine concentration were 0.868, 0.866, 0.870 in the stages 2 (cut-point 14.80㎛), 5 (cut-point 3.50㎛), and 8 (cut-point 0.52㎛) from Marple's 8-stage cascade impactor, respectively. In conclusion, RSP concentration in PC game room has a tendency to increase by smoking. Therefore, it is suggested that the effective air control system and education program be applied for PC game room.

When constructing tunnels, it is important to understand structural, geological and hydrogeological conditions. Geumgeong tunnel that has been constructed in Mt. Geumjeong for the Gyeongbu express railway induced rapid drawdown of groundwater in the tunnel construction area and surroundings. This study aimed to analyze groundwater flow system and baseflow using long-term monitoring and groundwater flow modeling around Geumgeong tunnel. Field hydraulic tests were carried out in order to estimate hydraulic conductivity, transmissivity, and storativity in the study area. Following the formula of Turc and groundwater flow modeling, the annual evapotranspiration and recharge rate including baseflow were estimated as 48% and 23% compared to annual precipitation, respectively. According to the transient modeling for 12 years after tunnel excavation, baseflow was estimated as 9,796 - 9,402 m3/day with a decreasing tendency.

Groundwater recharge characteristics in a fractured granite area, Mt. Geumjeong, Korea. was interpreted using bedrock groundwater and wet-land water data. Time series analysis using autocorreclation, cross-correlation and spectral density was conducted for characterizing water level variation and recharge rate in low water and high water seasons. Autocorrelation analysis using water levels resulted in short delay time with weak linearity and memory. Cross-correlation function from cross-correlation analysis was lower in the low water season than the high water season for the bedrock groundwater. The result of water level decline analysis identified groundwater recharge rate of about 11% in the study area.

This study was conducted to assess the characteristics of pigment wastewater and the removal rates of appropriate treatment by physical, chemical and biological process, and the possibility of reuse for effluent. Based on the results, the wastewater qualities of pigment were pH 5.1±3.4, temperature 43.0±5.0℃ BOD 1,431.4±589.6㎎/ℓ, COD 2,282.8±66.5㎎/ℓ, turbidity 1,340±82ONTU, color 243.0±147.Ounit, Pb 36.5±9.5㎎/ℓ and Cr^+6 10.3±1.3㎎/ℓ, respectively. The removal rates of adsorption by activated carbon and filter process were BOD 40.6%, COD 57.0%, turbidity 89.6%, color 87.2%, Pb 86.0% and Cr^+6 10.6%, respectively. And the removal rates of reduction, neutralization, coagulation and air floatation process were BOD 18.2%, COD 24.3%, turbidity 74.3%, color 56.7%, Pb 68.6% and Cr^+6 97.8%, respectively. The removal rates of activated sludge process were BOD 95.9%, COD 86.0%, turbidity 27.8%, color 25.2%, Pb 26.9% and Cr^+6 50.0%, respectively. The total removal rates of treatment by physical, chemical and biological process were BOD 98.0%, COD 95.4%, turbidity 98.1%, color 95.8%, Pb 97.0% and Cr^+6 99.0%, respectively. According to the test results for possibility of reuse with coagulation-adsorption by activated carbon process of effluent, COD was higher than that of raw water and others were similar to that of raw water, thus, it is considered to be reused.