79
Environmental Fate Models
and organic chemicals, and their effects on the ecosystem, including fsh,
invertebrates, and aquatic plants. It is a valuable tool for ecologists, biologists, water quality modelers, and anyone involved in performing ecological risk assessments for aquatic ecosystems. From the beginning, AQUATOX
was developed as an applied model for use by environmental analysts. It
incorporates constructs from classic ecosystem and chemodynamic models.
A private consulting frm, under contract with the EPA, performed an extensive search of the environmental literature and identifed 173 articles describing the use of AQUATOX (EPA, 2013). AQUATOX holds the most potential
for generalized risk assessment use and also has potential for use in regulatory scenarios including development of water quality criteria, total maximum daily loads, and analysis of management alternatives. One detailed
AQUATOX case study was concerned with the effects of a pesticide (dieldrin)
on largemouth bass in an Iowa reservoir (Mauriello and Park, 2002). The
objective of maintaining a viable recreational bass fshery was used to evaluate alternative strategies for reducing risks to the bass population. The model
quantifed the potential effectiveness of alternative management strategies
and provided feedback for policy refnements.
Another multimedia modeling approach is the fugacity concept, developed by Mackay and coworkers (Table 5.3). It is fundamental to current environmental modeling where fugacity is defned as the “escaping tendency”
of a chemical substance from a phase in terms of mass transfer coeffcients.
The concept is described in the book Multimedia Environmental Models: The
Fugacity Approach (Mackay, 2001) and many applications are discussed in the
book Handbook of Chemical Mass Transport in the Environment (Thibodeaux
and Mackay, 2010). Some specifc examples of the use of the fugacity concept
include predicting the environmental fate of multiple chemicals (Cahill et al.,
2003) and modeling pharmaceutical residues in sewage (Khan and Ongerth,
2004). The Cahill et al. study used the framework of the Mackay fugacity
model, but with a few key changes: (1) the model handled up to four independent chemical species which allowed for the analyses of the parent chemical
and degradation products; (2) the model is dynamic instead of steady-state
and can predict chemical concentrations in each medium as a function of
time, so it can measure the dissipation of a chemical; and (3) the evaluative
TABLE 5.3
Fugacity Models
Name
Description
Reference
Fugacity
Distribution-based models that incorporate all
http://www.kch.tul.cz/
Models I-III
environmental compartments and are based on the
sedlbauer/fugacity_
steady-state fuxes of pollutants across compartment model.pdf
interfaces. Other fugacity models include the
multimedia fugacity model and multimedia
equilibrium criterion model
Environmental Fate Models
and organic chemicals, and their effects on the ecosystem, including fsh,
invertebrates, and aquatic plants. It is a valuable tool for ecologists, biologists, water quality modelers, and anyone involved in performing ecological risk assessments for aquatic ecosystems. From the beginning, AQUATOX
was developed as an applied model for use by environmental analysts. It
incorporates constructs from classic ecosystem and chemodynamic models.
A private consulting frm, under contract with the EPA, performed an extensive search of the environmental literature and identifed 173 articles describing the use of AQUATOX (EPA, 2013). AQUATOX holds the most potential
for generalized risk assessment use and also has potential for use in regulatory scenarios including development of water quality criteria, total maximum daily loads, and analysis of management alternatives. One detailed
AQUATOX case study was concerned with the effects of a pesticide (dieldrin)
on largemouth bass in an Iowa reservoir (Mauriello and Park, 2002). The
objective of maintaining a viable recreational bass fshery was used to evaluate alternative strategies for reducing risks to the bass population. The model
quantifed the potential effectiveness of alternative management strategies
and provided feedback for policy refnements.
Another multimedia modeling approach is the fugacity concept, developed by Mackay and coworkers (Table 5.3). It is fundamental to current environmental modeling where fugacity is defned as the “escaping tendency”
of a chemical substance from a phase in terms of mass transfer coeffcients.
The concept is described in the book Multimedia Environmental Models: The
Fugacity Approach (Mackay, 2001) and many applications are discussed in the
book Handbook of Chemical Mass Transport in the Environment (Thibodeaux
and Mackay, 2010). Some specifc examples of the use of the fugacity concept
include predicting the environmental fate of multiple chemicals (Cahill et al.,
2003) and modeling pharmaceutical residues in sewage (Khan and Ongerth,
2004). The Cahill et al. study used the framework of the Mackay fugacity
model, but with a few key changes: (1) the model handled up to four independent chemical species which allowed for the analyses of the parent chemical
and degradation products; (2) the model is dynamic instead of steady-state
and can predict chemical concentrations in each medium as a function of
time, so it can measure the dissipation of a chemical; and (3) the evaluative
TABLE 5.3
Fugacity Models
Name
Description
Reference
Fugacity
Distribution-based models that incorporate all
http://www.kch.tul.cz/
Models I-III
environmental compartments and are based on the
sedlbauer/fugacity_
steady-state fuxes of pollutants across compartment model.pdf
interfaces. Other fugacity models include the
multimedia fugacity model and multimedia
equilibrium criterion model