The Removal of Atmospheric Gases by Particulate Matter

  1. David R. Schryer
  1. Julian Heicklen

Published Online: 21 MAR 2013

DOI: 10.1029/GM026p0093

Heterogeneous Atmospheric Chemistry

Heterogeneous Atmospheric Chemistry

How to Cite

Heicklen, J. (1982) The Removal of Atmospheric Gases by Particulate Matter, in Heterogeneous Atmospheric Chemistry (ed D. R. Schryer), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM026p0093

Author Information

  1. Department of Chemistry and Center for Air Environment Studies, Pennsylvania State University, University Park, Pennsylvania 16802

Publication History

  1. Published Online: 21 MAR 2013
  2. Published Print: 1 JAN 1982

ISBN Information

Print ISBN: 9780875900513

Online ISBN: 9781118663813

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Keywords:

  • Atmospheric chemistry—Addresses, essays, lectures

Summary

The conditions for removal of an atmospheric pollutant by water droplets or on the surface of an aerosol have been investigated. For pollutants which do not react in water droplets or on aerosol surfaces, the removal lifetimes of the pollutant equal the atmospheric turnover lifetimes (∼106 sec) of the droplets or aerosol if (1) the ratio of the Henry's law constant to the fraction of air occupied by water droplets is less than 1 for water droplets, or (2) the ratio of the vapor-phase concentration of the pollutant to the number of aerosol sites occupied at equilibrium is less than 1 for aerosols.

For pollutants that do undergo reactions in water droplets or on aerosol surfaces, the removal rate can be enhanced over the nonreactive removal rate only if the effective removal rate coefficient for the pollutant in the water droplet or on the aerosol surface exceeds the reciprocal turnover lifetime of the particulate matter (i.e., for removal rate coefficients greater than ∼10−6 sec−1). For the chemicalr eaction to be rate-controlling it is also necessary that chemical reaction be sufficiently slow so that diffusion of the gaseous pollutant to the droplet or aerosol is not rate controlling. Chemical reaction is rate controlling if the chemical reaction rate coefficient lies between 10−2 and 10−6 sec−1.