John Wiley & Sons, Ltd.

On the formulation of environmental fugacity models and their numerical solutions

Multimedia models based on chemical fugacity, solved numerically, play an important role in investigating and quantifying the environmental fate of chemicals such as persistent organic pollutants (POPs). These models have been utilised extensively in the study of the local and global distribution of chemicals in the environment. This paper describes potential sources of error that may arise from the formulation and numerical solution of environmental fugacity models. We derive a general fugacity equation for the rate of change of mass in an arbitrary volume (e.g. an environmental phase). The derivation of this general equation makes clear a number of assumptions that are often not articulated but can be important for the successful application of multimedia fugacity models. It shows that the homogeneity of fugacity and fugacity capacity in a volume (the homogeneity assumption) is fundamental to the formulation of discretised fugacity models. It also shows that when using the fugacity rather than mass as the state‐variable, correction terms may be necessary to accommodate environmental factors such as varying phase temperatures and volume. Neglect of these can lead to conservation errors. We illustrate the manifestation of these errors using heuristic multimedia fugacity models. We also show that there are easily avoided errors that can arise in mass state‐variable models if variables are not updated appropriately in the numerical integration scheme. This article is protected by copyright. All rights reserved

Customer comments

No comments were found for On the formulation of environmental fugacity models and their numerical solutions. Be the first to comment!