Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Equilibrium and atmospheric semi-volatiles

Conference ·
OSTI ID:369994
; ;  [1]
  1. Univ. of North Carolina, Chapel Hill, SC (United States); and others
Recent investigations in our laboratory have shown that fresh combustion emission tend to come into equilibrium in the atmosphere very rapidly. In order for this to occur, semivolatiles associated with particles must have the ability to rapidly off-gas as they mix and dilute in the air. Experiments using a large gas phase semivolatile stripping device show that considerable loss of particle phase semivolatiles occurs on time scales of seconds. We have also observed that extent of partitioning is different on different types of combustion particles. For example, alkanes partition to a greater extent on diesel exhaust particles then they do on wood soot particles. The reverse is true for PAHs. Humidity effects on partitioning are also different on different types of particles and may even be different among compounds of the same classes. For example a chamber based partitioning relationship (similar to that of Pankow and co workers) predicted that flouranthene partitioning to be particle phase increased with increasing humidity, while flourene partitioning decreased under the same conditions.
OSTI ID:
369994
Report Number(s):
CONF-960376--
Country of Publication:
United States
Language:
English