The characteristic study of TSP, PM2.5 similar to 10 and PM2.5 in the rural site of central Taiwan

The total suspended particle (TSP), PM2.5 similar to 10 (aerodynamic diamet er less than 10 mu m) and PM2.5 concentration (aerodynamic diameter less th an 2.5 mu m) concentrations were sampled by PS-1 and Universal sampler on t he roof (25 m) of the Medical and Engineering Building in the campus of Hun gkuang Institute of Technology (HKIT) which is located at a height of 500 m on Da Du Mountain. The results indicated that average TSP, PM2.5 similar t o 10 and PM2.5 concentrations are 0.42, 0.34 and 0.019 mg/m(3) in the day t ime, respectively and are 0.32, 0.26 and 0.017 mg/m(3) in the night time, r espectively. The ratios of PM2.5 similar to 10/TSP were from 76% to 85% and from 50% to 91% for day and night period, respectively. It indicated that the major composition in the total suspended particles was PM2.5 similar to 10 in the rural site. The relationship between TSP and PM2.5 similar to 10 is TSP = 1.16PM(2.5 similar to 10) + 0.027 and TSP = 1.01PM(2.5 similar to 10), + 0.058 in the day and night time, respectively. The correlation coef ficient (R-2) is 0.98 and 0.97 for day and night period, respectively. The relationship between PM2.5 similar to 10 and PM2.5 is PM2.5 = 0.0005PM(2.5 similar to 10) + 0.019 and PM2.5 = 0.037PM(2.5 similar to 10) + 0.0076 in t he day and night period, respectively. The correlation coefficient (R-2) is 3E-5 and 0.67 for day and night period, respectively. The relationships be tween TSP, PM(2.5)similar to 10, PM2.5 particle concentrations and wind spe ed (R-2) in the day time are 0.71, 0.64, 0.43, respectively and are 0.83, 0 .79, 0.57, respectively in the night time. The proposed reasons are that th ere are more activities caused by people (students) and natural living anim als which absorbed some of the particles during the day time. Thus, the cor relation coefficients for the night time are better than those of day time. The particle size distributions are both bimodel in the day and night time . The major peaks in the day time appear in the particle diameter between 0 .031 similar to 0.056 mu m and 3.16 similar to 5.62 mu m in the day period and appear between 0.017 similar to 0.031 mu m and 1.78 similar to 3.16 mu m in the night period. The results indicate that the particle size distribu tion in the day time tends to be of larger particle size mode than the nigh t time. (C) 1999 Elsevier Science B.V. All rights reserved.