Sectored Planters for Phytoremdiation Studies

Field practice of phytoremediation involves complicated and variable conditions. There is a need for methods that can transpose the contaminated site to a controlled greenhouse environment so that screening of phytoremediators and evaluation of efficacy can be carried out objectively. The “sectored planter” method is designed to compare and evaluate preselected phytoremediators and offers validation to a field experiment. The method described here recapitulates our recent work at a managed coastal phytoremediation site on Oahu, Hawaii where deep coastal soil contamination of petroleum hydrocarbon occurred. The contaminants are of relatively low concentrations and unevenly distributed, so field evaluation of efficacy would be impractical. Because the contaminants were accumulated at the third soil layer beneath a top sandy loam and a middle silt layer, a trisector planter was designed to simulate the field conditions, including soil profiles and field management of the three selected tree species. Known quantities of six diesel-fuel components were used to spike soils in the third or bottom section of the planter. The reduction of concentrations of these compounds was determined and results on the three tree species and the no-plant control were compared after 200 d growth in the greenhouse. The experience obtained in this experiment suggests that the “sectored planter” method offers a wide range of applications in phytoremediation studies. These possibilities are discussed.