Migration simulations

American Institute of Chemical Engineers. Advanced Simulators Migrate to PCs, Chem. Eng. Fiog. 90 (Oct. 1994) 1.3-14. 

CASTLE L., HART A., HOLMES M.J., OLDRiNG P.K.T., (2006), An approach to stochastic modelling of consumer exposure for any substance from canned foods using simulant migration data. Food Additives and Contaminants, in press. 

The control over the uptake experiment in a chromatographic column and interpretation of results is even more difficult than with static experiments. For example the pH in dynamic experiments varies not only as a function of time but also spatially (as a function of the position in a column). On the other hand, chromatography is an efficient method to entirely remove certain solutes from solution, it is also used to simulate migration of pollutants in natural systems. 

This paper is the result of research conducted to evaluate the use of distribution coefficient (Kd) values and mineral solubility data to simulate migration of contaminants from disposal sites of oil shale waste planned in the Piceance Creek Basin of western Colorado. In a broad context, the purpose of the research was to simulate geochemiad impacts of the accidental discharge of oil shale leachate into the subsurface. The aquifer of concern was a sandstone member of the Uinta Formation, the bedrock that underlies potential disposal sites for oil shale waste near Parachute, Colorado. The contaminant fluid was a leachate derived firom the Lawrence Livermore L2 modified in-situ processed shale. 

Simulating Migration of Polymer Chains, Methods, Fig. 1 Confonnation of a 30-bead chain in a linear shear flow at different times. The chain shown will exhibit a periodic tumbling motion if observed for long periods of time... 

Figure 14.10 Simulated migration profiles generated from the proposed model (equation 23) and the rigorons model (Equation 14.27] for a = 1 and 5, Dq = 10 cm /s and Lp = 10 pm. Reproduced with permission from Chung and coworkers, Food Additives and Contaminants, 2002, 19, 6, 611 [22],...

This guidance document describes experimental protocols to be employed for simulating migration. It addresses classes of migrating substances, types of food, and duration and temperature at which the contact occurs. It further describes the data quality requirements for migration data, and the relationship between migration and human dietary exposure to a migrating substance. 

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