Phytoremediation of 137cesium and 90strontium from solutions and low-level nuclear waste by Vetiveria zizanoides

Vetiver grass (Vetiveria zizanoides) L. Nash plantlets when tested for their potential to remove 90Sr and 137Cs (5×103 k Bq l−1) from solutions spiked with individual radionuclide showed that 94% of 90Sr and 61% of 137Cs could be removed from solutions after 168 h. When both 90Sr and 137Cs were supplemented together to the solution, 91% of 90Sr and 59% of 137Cs were removed at the end of 168 h. In case of 137Cs, accumulation occurred more in roots than shoots, while 90Sr accumulated more in shoots than roots. When experiments were performed to study the effect of analogous elements, K+ ions reduced the uptake of 137Cs, while 90Sr accumulation was found to decrease in the presence of Ca2+ ions. Plants of V. zizanoides could also effectively remove radioactive elements from low-level nuclear waste and the level of radioactivity was reduced below detection limit at the end of 15 days of exposure. The results of the present study indicate that V. zizanoides may be a potential candidate plant for phytoremediation of 90Sr and 137Cs.