High explosive compounds such as RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) from military shooting ranges may pose human health and ecological risks. In pot culture studies, Indian jointvetch (Aeschynomene indica) was evaluated as a candidate indigenous plant species for phytoremediation of RDX. The concentration of RDX ranged from blank to 10, 100, 150, 200, 300, and 400 mg/kg, and an Indian jointvetch seedling (approximately 5 cm) was transplanted into a pot containing shooting range soil. The pot culture lasted for 21 days in a controlled growth chamber. The toxic effects of RDX, such as necrosis on leaf edges, biomass reduction, and leaf/stem abscission, started with a 100 mg/kg to 400 mg/kg treatment. The effective concentration (EC50) based on dry weight (n=10 for each treatment) for above-ground, root, and whole plant was 222.5, 69.6, and 181.4 mg-RDX/kg-soil, respectively. The analysis of RDX in the plant (n = 3) indicated a log-linear relationship between plant and soil RDX concentrations, with 95% of RDX translocated to the above-ground part. The maximum concentration was 6,259.9 mg/g-DW in the 400 mg-RDX/kg treatment. Furthermore, the cultivation of Indian jointvetch enhanced RDX removal by over 10% compared to the control group that did not culture the plant. Therefore, Indian jointvetch is a prominent native plant species for the phytoremediation of RDX at a military shooting range.

Keywords: EC50, Explosives, Indian jointvetch, Phytoremediation, RDX, Shooting range