Prediction of multicomponent inorganic atmospheric aerosol behavior. Ansari, A., S. and Pandis, S., N. Atmos. Environ., 33:745-757, 1999.
abstract   bibtex   
Many existing models calculate the composition of the atmospheric aerosol system by solving a set of algebraic equations based on reversible reactions derived from thermodynamic equilibrium. Some models rely on an a priori knowledge of the presence of components in certain relative humidity regimes, and often fail to accurately predict deliquescence point depression and multistage aerosol growth. The present approach, relying on adjusted thermodynamic parameters of solid salts and a state of the art activity coefficient model, directly minimizes the Gibbs free energy (according to thermodynamic equilibrium principles) given temperature, relative humidity and the total (gas plus aerosol) ammonia, nitric acid, sulfate, sodium, and hydrochloric acid concentrations. A direct minimization, while requiring nb additional assumptions in its algorithm, allows the elimination of many of the assumptions used in previous models such as divided relative humidity (rh) and composition domains where only certain reactions are assumed to occur and constant DRH values despite varying temperature and composition. Moreover, the current approach predicts aerosol deliquescence and efflorescence behavior explaining the existence of supersaturated aerosol solutions. A comparison is conducted between our approach and available experimental results under several conditions. The current model agrees with experimental results for single salt systems although it shows sensitivity to thermodynamic parameters used in the minimization algorithm. A set of Delta G(f)(0) for solid salts is estimated that is consistent with available laboratory measurements and significantly improves model performance. I;or multicomponent systems, the current approach with adjusted Delta G(f)(0) accurately reproduces observed multistage growth patterns and deliquescence point depression over a broad temperature range. Finally, the direct Gibbs free energy minimization accurately reproduces aerosol efflorescence behavior. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Carnegie Mellon Univ, Dept Chem Engn, Pittsburgh, PA 15213 USA. Carnegie Mellon Univ, Dept Engn & Publ Policy, Pittsburgh, PA 15213 USA.
@article{
 title = {Prediction of multicomponent inorganic atmospheric aerosol behavior},
 type = {article},
 year = {1999},
 pages = {745-757},
 volume = {33},
 id = {7379b9a9-bd67-34e3-adb8-2cbc3f5fed38},
 created = {2014-10-08T16:28:18.000Z},
 file_attached = {false},
 profile_id = {363623ef-1990-38f1-b354-f5cdaa6548b2},
 group_id = {02267cec-5558-3876-9cfc-78d056bad5b9},
 last_modified = {2017-03-14T17:32:24.802Z},
 read = {false},
 starred = {false},
 authored = {false},
 confirmed = {true},
 hidden = {false},
 citation_key = {Ansari:AE:1999a},
 source_type = {article},
 private_publication = {false},
 abstract = {Many existing models calculate the composition of the
atmospheric aerosol system by solving a set of algebraic equations
based on reversible reactions derived from thermodynamic
equilibrium. Some models rely on an a priori knowledge of the
presence of components in certain relative humidity regimes, and
often fail to accurately predict deliquescence point depression and
multistage aerosol growth. The present approach, relying on
adjusted thermodynamic parameters of solid salts and a state of the
art activity coefficient model, directly minimizes the Gibbs free
energy (according to thermodynamic equilibrium principles) given
temperature, relative humidity and the total (gas plus aerosol)
ammonia, nitric acid, sulfate, sodium, and hydrochloric acid
concentrations. A direct minimization, while requiring nb
additional assumptions in its algorithm, allows the elimination of
many of the assumptions used in previous models such as divided
relative humidity (rh) and composition domains where only certain
reactions are assumed to occur and constant DRH values despite
varying temperature and composition. Moreover, the current approach
predicts aerosol deliquescence and efflorescence behavior
explaining the existence of supersaturated aerosol solutions. A
comparison is conducted between our approach and available
experimental results under several conditions. The current model
agrees with experimental results for single salt systems although
it shows sensitivity to thermodynamic parameters used in the
minimization algorithm. A set of Delta G(f)(0) for solid salts is
estimated that is consistent with available laboratory measurements
and significantly improves model performance. I;or multicomponent
systems, the current approach with adjusted Delta G(f)(0)
accurately reproduces observed multistage growth patterns and
deliquescence point depression over a broad temperature range.
Finally, the direct Gibbs free energy minimization accurately
reproduces aerosol efflorescence behavior. (C) 1999 Elsevier
Science Ltd. All rights reserved. C1 Carnegie Mellon Univ, Dept
Chem Engn, Pittsburgh, PA 15213 USA. Carnegie Mellon Univ, Dept
Engn & Publ Policy, Pittsburgh, PA 15213 USA.},
 bibtype = {article},
 author = {Ansari, A S and Pandis, S N},
 journal = {Atmos. Environ.}
}
Downloads: 0