Analysis of the correlation between measurement methods in the quantitative measurement of fine dust (PM-2.5, PM-10) Park, Tae Shin Environmental Engineering Major The Graduate School of Environmental Studies Kwangwoon University There are two methods...
Analysis of the correlation between measurement methods in the quantitative measurement of fine dust (PM-2.5, PM-10) Park, Tae Shin Environmental Engineering Major The Graduate School of Environmental Studies Kwangwoon University There are two methods for measuring dust in the air: the gravimetric measurement method and the beta-ray absorption method. However, the gravimetric measurement method has time constraints as it requires 24 hours for collection, and the beta-ray absorption method allows for real-time measurement, but has the disadvantage of securing installation space and high price. A method that can replace this is the light scattering method, which allows real-time measurement and has no restrictions on installation location due to the small size of the equipment. Among the various dust measurement methods announced by the Ministry of Environment in 2016, the light scattering method was deleted as it was rarely used due to its large error rate. However, currently, due to various research and technological developments, the measurement error of the light scattering method has been greatly improved. Considering this, in this study, I attempted to compare and evaluate the correlation between three different measuring instruments using the beta ray absorption method, the gravimetric measurement method, and the light scattering method by simultaneously installing and measuring the fine dust concentration. To compare the beta ray absorption measurement concentration with the gravimetric measurement concentration, calibration of the beta ray measuring instrument was performed. The fine dust concentration ratio between the calibrated the gravimetric measurement and beta-ray absorption measurement was 96% for PM-2.5 and 107% for PM-10, and the correlation coefficient was 0.9614 for PM-2.5 and 0.9250 for PM-10. Measurements by beta ray absorption and light scattering meter were conducted at hourly intervals, but comparative analysis was conducted by applying the average value over a 24-hour period according to the result notation method specified in the air pollution process test standards. The daily average fine dust concentration ratio of the light scattering and the beta ray absorption meter was measured at 71% and 81% for PM-2.5 and PM-10, respectively, and when comparing only the PM-2.5 results of 15㎍/㎥ or more, it was found to be slightly lower at 54%. The correlation coefficient for PM-2.5 was 0.6722~0.9112, and for PM-10 was 0.8230~0.9405. In the case of PM-10, the concentration ratio was 80% in the high concentration section of 50㎍/㎥ or more on an annual basis among the air environment standards, which was not a significant difference compared to the entire section. In order to investigate the effect of humidity, the concentration and correlation coefficient below and above 60% humidity were compared. As a result, for PM-2.5, a fine dust concentration ratio of 74% and a correlation coefficient of 0.8856 were obtained at 60% or less. Above 60%, a fine dust concentration ratio of 69% and a correlation coefficient of 0.9124 were obtained. For PM-10, a fine dust concentration ratio of 85% and a correlation coefficient of 0.7847 were obtained at humidity below 60%, and a fine dust concentration ratio of 77% and a correlation coefficient of 0.9426 were obtained at humidity above 60%. And for PM-2.5, a fine dust concentration ratio of 68% and a correlation coefficient of 0.9605 were obtained at humidity above 70%. For PM-10, a fine dust concentration ratio of 76% and a correlation coefficient of 0.9553 were obtained. As a result of the study, it was confirmed that the deviation between the beta ray absorption concentration and the light scattering concentration used for real-time measurement was greatly improved and similar measurement values were obtained. As a result of comparing fine dust concentration ratio between light scattering and beta ray absorption meters over time at high concentration, PM-2.5 had a somewhat low correlation of 50%. However, PM-10 showed a high correlation of 98%, which is similar as the fine dust concentration ratio of the nearby network of national measurement. It was considered that the difference in correlation depending on particle size was due to the different shapes and densities of fine dust, which resulted in differences depending on the viewing angle. It was found that the correlation was relatively high and the deviation was small in the measurement of PM-10 with large particle size. It is believed that light scattering equipment can be used in place of the shortcomings of beta radiation measuring instruments for monitoring such as responding to fine dust in high concentration cities and environmental impact assessment.