Abstract
We developed “Geo-environment and root growth prediction model” to forecast time-space changing of soil water and chemical environment under existence of plant root in ground. The developed model will be contributed to optimize geo-environment for phytoremediation. Phytoremediation is purification of ground contaminated by toxic heavy metals using absorption of plants. However, it depends on water holding capacity of soil, holding capacity of chemical substance of soil, growth of plant and climate conditions. This model can clarify relationships between transfer of soil water and water soluble substance in unsaturated-ground and absorption of them by root uptake. This two-dimensional analysis consisted of equation of water movement and advection-diffusion equation considering absorption of soil water and water soluble substance by root with finite-difference method. This paper shows effectiveness of the developed model by calculating several SWCC conditions of soils. In addition, contribution degrees of remediation by single root uptake was clarified. The conclusions are as follows; 1) Absorption of water and water soluble substace were depended on matrix potential of soils. The higher water retention capacity the soil had, the lower root uptake occurred under same effective saturation degree. 2) In case available moisture of soil was lower, contribution of root uptake was higher.
