A mathematical model to assist phytoremediation management and evaluation

Abstract

Phytoremediation is the use of plants and their associated microbes for environmental cleanup. The use of phytoremediation for soil cleanup faces a number of challenges of which leaching of soil contaminants below the rooting zone poses a significant environmental threat. Partitioning of contaminants between plant uptake and leaching is the focus of this Master’s Project (MP). An improved mathematical model to represent phytoremediation processes are developed that couple the hydrological balance and soil contaminant balance for a dynamic vegetation system (i.e. rooting zone depth and leaf area are changing in time during the remediation period). Two different measures of phytoremediation efficiency are then assessed with different water supply amount & frequency, soil & plant properties and climatic conditions. It is found that water supply pattern is a first-order factor controlling the efficiency of phytoremediation when viewed from the perspective of maximizing plant-water uptake of contaminants. Climate change could also exert significant influence by affecting growth patterns of the plant. Additionally, a geospatial analysis tool is also created with the model to locate areas where phytoremediation may be an effective management option, when the climatic and soil datasets are available. With this combined geospatial tool and the newly proposed model, phytoremediation managers can evaluate the potential phytoremediation efficiency according to their specific situation.