Development of drone-based filter sampling system for carbonaceous aerosol analysis using thermal–optical transmittance method

Application of a drone-based, high-volume (38 L min⁻¹) sampling system developed for time-resolved monitoring of elemental and organic carbon (EC and OC) is demonstrated in this study. Filter samples collected by the samplers were analyzed by a laboratory-based, thermal-optical transmittance (TOT) method of the National Institute for Occupational Safety and Health using a Sunset Laboratory OC-EC analyzer. The EC, OC, and total carbon (TC) results for filter samples collected by the high-volume (38 L min⁻¹) sampler are compared to those obtained by a low-volume (4 L min⁻¹) sampler at ground level. Prior to the use of the developed high-volume sampler at 150 m, three 30-min air samples, taken from 11:00 to 15:00, and three 1-h samples, taken between 15:00 and 22:00, were collected at ground level by the drone-based system. For reference, the low-volume filter sample was collected over the 12-h period on the same day. In addition, particulate matter and black carbon concentrations were obtained as supportive data. In the ground-level test, the average EC, OC, and TC concentrations determined with the high-volume (drone) samples agree well with those determined with the 12-h, integrated, low-volume sample. Further field samplings on the ground and at 150-m were conducted over 2 days to assess the developed drone-based sampling system for measurement of carbonaceous aerosols. The EC, OC, and TC concentrations at a 150-m altitude were successfully examined via drone-based, high-volume sampling and TOT analysis.