Physiological responses of Acorus calamus and reed under composite heavy metal stress and their enrichment ability

It was studied that the aquatic plant Acorus calamus and reed affected the enrichment ability of compound heavy metals (i. e. V, Cr and Cd) and physiological response and the two plants repair effects of polluted water were investigated by heavy metals. Results show that the tolerance index of two plants decreases with heavy metals concentration increasing in water body, whereas the growth of the Acorus calamus is better than that of reed. Under different concentrations of heavy metals, both Acorus calamus and reed show the strongest enrichment ability of Cd, followed by Cr, while the enrichment ability of V is relatively weak. Under same heavy metal concentration, Acorus calamus on the total enrichment quantities of three kinds of heavy metals are better than those of reed. When the mass concentration of heavy metal is 15 mg·L^-1, the enrichment of three heavy metals by Acorus calamus is 1065.02, 1754.80 and 4372.40 mg·kg^-1 for V, Cr and Cd, respectively. The enrichment index of Acorus calamus underground part of V, Cr and Cd is 2.1, 1.5 and 1.8 times better than that of reed. It is concluded that Acorus calamus is more suitable for the remediation of heavy metal pollution by V, Cr and Cd.