Phytoremediation of BTEX contaminated soil by Canna×generalis.

Bioaccumulation experiments showed that the canna (Canna×generalis) could accumulate BTEX (benzene, toluene, ethylbenzene and xylenes) from root zone and rhizome zone soil and translocate these compounds to the shoot. A comparison among these compounds showed that the sequences for accumulation in the root, rhizome and shoot were strongly related to their physicochemical properties (i.e. K(ow) values and molecular weight). For removal efficiency, the canna could remove about 80% of BTEX in the root zone and rhizome zone soil in 21 days. In addition, the removal efficiency in BTEX contaminated soil with 40% water content was a little higher than that found with 20% soil water content. This result indicated that the soil water content should also be considered when phytoremediation is employed.