This is consistent with the studies by LIPHADZI and KIRKHAM [29]. Although EDTA played an important role in enhancing the concentrations of As and Cd in giant reed shoots, especially that of Pb at high level treatment (Fig. 2), EDTA is non-biodegradable, and possesses high environmental persistence of soluble chelate-heavy metal complexes in soil as well as toxicity and risk of possible leaching to groundwater [7]. Therefore, AA, CA and sepiolite are better than EDTA in enhancing phytoremediation efficiency of giant greed.