Modeling of the sorption and diffusion processes of volatile organic air pollutants in grape fruits

A mathematical model for the description of the sorption and diffusion proc esses of gaseous toluene and p-xylene in fruits of grape has been proposed. This model is based on the Fick's II low regarding a particle with a spher ical shape (such as the berry of grapevine) and describes changes of air po llutant concentrations in different layers of the fruit, that is, the wax, peel, and pulp, during an exposure to contaminated air. The mass transfer c oefficient and diffusion coefficients in the respective layers can be estim ated using the experimental values. The theoretical data and the results fr om the exposure under steady-state laboratory conditions were compared and showed a good applicability of the proposed model for the prediction of vol atile air pollutant partitioning in grape berries.