Sampling and Analytical Methods Development for Dry Deposition Monitoring

摘要

Acid deposition is the transfer of acidic substances to the earth's surface by wet or dry deposition. Dry deposition includes all processes by which airborne contaminants are removed from the atmosphere at the earth's surface, excluding those processes directly aided by precipitation, and contributes substantially to the acidic deposition burden. The U.S. Environmental Protection Agency (EPA) plans to implement a dry deposition monitoring network. The constitutents of interest are HNO3, NO2, SO2, NH3, NH4+, NO3-, SO4(2-), H+ (acidity), and O3. The objective of the current research is to investigate sampling and analysis methods for these constituents to identify those methods that appear most promising for network deployment. The culmination of the current project is a field study conducted in the Research Triangle Park, North Carolina between August and December of 1986. The main objectives of the study were to conduct measurements of selected airborne gaseous and particulate acidifying species using different types of samplers and to evaluate the differences observed under field sampling conditions.