title: Simulating uptake and transport of TNT by plants using STELLA.
abstract: Understanding the uptake and transport of soil organic contaminants by plants is crucial to a successful application of phytoremediation technique. This study investigated the removal of 2,4,6-trinitrotoluene (TNT) from a contaminated sandy soil by a poplar tree (Populus fastigiata) through the examinations of temporal variations of xylem water potential, leaf water transpiration, and root water and TNT uptake. A dynamic model for Uptake and Translocation of Contaminants from a Soil-Plant ecosystem (UTCSP), developed using the STELLA software package, was modified for the purpose of this study. The model was calibrated using laboratory measurements prior to its application. Simulation results showed that about 25% of TNT was removed from the soil by the poplar tree in 90 days. Simulations further revealed that the rates of water and TNT up taken by roots had a typical diurnal variation pattern: increasing during the day and decreasing during the night, resulting from daily variations of xylem water potentials that were caused by leaf water transpiration. In general, the storage of TNT mass in the roots decreased with time and occurred partially because of the low availability of soil TNT as time elapsed and partially because of the biodegradation of TNT in the plant tissues. This study suggests that the UTCSP model could be a useful tool for estimating phytoremediation of soil TNT by a plant.
authors.affiliation: Department of Water Resources, St. Johns River Water Management District, P.O. Box 1429, Palatka, FL 32178-1429, USA. ouyangy@ufl.edu <ouyangy@ufl.edu>
authors.forename: Ying
authors.initials: Y
authors.lastname: Ouyang
authors.forename: Cheng He
authors.initials: CH
authors.lastname: Huang
authors.forename: Dong Yi
authors.initials: DY
authors.lastname: Huang
authors.forename: Dian
authors.initials: D
authors.lastname: Lin
authors.forename: Lihua
authors.initials: L
authors.lastname: Cui
mesh_terms: D001673:Biodegradation, Environmental; D001692:Biological Transport; D002940:Circadian Rhythm; D003198:Computer Simulation; D008954:Models, Biological; D018517:Plant Roots / Q000378:metabolism; D032107:Populus / Q000378:metabolism*; D012984:Software; D012989:Soil Pollutants / Q000378:metabolism*; D014303:Trinitrotoluene / Q000378:metabolism*; D014867:Water / Q000378:metabolism; D052584:Xylem / Q000378:metabolism
chemical_list: D012989:Soil Pollutants; D014867:Water; D014303:Trinitrotoluene