Multimedia compartmental models

Based on the descriptions of spatial variation in each environmental compartment, multimedia models can be categorized into multimedia compartmental models (MCMs) [3-20], spatial multimedia models (SMs) [21-24] and spatial multimedia compartmental models (SMCMs) [25-27]. MCMs assume homogeneous landscape properties in each medium and assume all environmental compartments are well mixed. SMs are collections of single-media models in which the output of one model serves as the input to the others. Each individual model in the SMs is a spatial model describing the variation of environmental properties in one or more directions. SMCMs are similar to MCMs, but consider one or more environmental compartments as nonuniform regions. 

Table 2 Using ready and inherent biodegradability data to derive input data for the EQui-librium Criterion (EQC) model [35]. Multimedia fate models like the EQC model require compartmental half-lives for air, water, soil, and sediment. The scheme in the table is offered as an interim procedure for assigning half-lives for input to such models. These are bulk half-lives (i.e., for the compartment as a whole). They are not to be interpreted as (necessarily) half-lives for any specific process, such as biodegradation. No assumptions which compromise their interpretation as bulk half-lives should be made, including, for example, the assumption that biodegradation is the important process and occurs in soil pore water only. Air half-lives are not addressed here and it is assumed that data for input to models are either measured or derived from AOPWIN or similar methodology.

Cohen Y, Cooter EJ (2002) Multimedia environmental distribution of toxics (Mend-Tox). I. Hybrid compartmental-spatial modeling framework. Pract Periodical Hazard Toxic Radioactive Waste Manag 6(2) 70-86... 

To understand the impact of individual processes on the compartmental distribution of DDT, model runs with a non-steady-state, zero-dimensional, multimedia mass balance box model (MPI-MBM) [Lammel (2004)] were conducted in addition to MPI-MCTM experiments. Parameterisations of intra- and intercompartmental mass exchange and conversion process in MPI-MBM are similar to those in MPI-MCTM. A detailed description of differences and a comparison of both models can be found in Lammel et al (2007). The DDT emissions were the global mean temporally varying DDT applications for the years 1950 to 1990. A repeating annual cycle around constant mean temperatures was simulated. Surface and air temperatures differ by 14 K constantly. 

Swann, R.L. Eschenroeder, A., Eds. Fate of Chemicals in the Environment - Compartmental and Multimedia Models for Predictions" ACS SYMPOSIUM SERIES No. 225, American Chemical Society Washington, D.C., 1983. 

Swann, R.L. and A. Eschenroeder, Eds. 1983. Fate of chemicals in the environment— Compartmental and multimedia model predictions. ACS Symposium Series 225. American Chemical Society, Washington, DC. 

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