Abstract
To evaluate dry deposition which is indispensable in estimating the effect of acid deposition on forest ecosystems and cultural properties, a 4-stage filter pack method (F0-F3), a technique to determine concentrations of air pollutants, was modified and technically evaluated. Usinga 0.8μm polytetrafluoroethylene filter as a first stage (F0), gaseous components can be separated completely from suspended particulate matters. Polyamide filter used as a second stage (F1) selectively collected HNO3, and to a lesser degreee also SO2, HCI and NH3. K2CO3 impregnated cellulose filters as a third stage (F2) and H3PO4 impregnated filters as a fourth stage (F3) can collect SO2 and HCI, and NH3, respectively. From these results, it is considered that SO2 and HCI should be calculated from the total amount of components on F1 and F2 filters, and NH3 from that on F1 and F3. A 4-stage filter pack method can be useful for dry deposition monitoring, when carried out according to detailed technical standards for measurement to maintain precision.
