The uptake of TcO-4 by plants: a mathematical description

A model describing the uptake of TcO-4 by spinach plants was developed. The equation relates both plant and soil parameters (e.g., growth, metabolism, concentration of TcO-4 and composition of the growth medium) to the concentration of Tc in the shoot of the plant. As the soil solution is the medium from which plants obtain nutrients and non-nutrients, the modeling parameters have been obtained from uptake experiments using nutrient solutions (= simulated soil solutions) as the growth medium. Two important model assumptions are: 1) that an equilibrium exists between TcO-4 in the plant and the growth medium and 2) that the leaf TcO-4 metabolism is a pseudofirst order reaction occurring in a non-constant volume.