Ecological restoration of arsenic contaminated soil by Arundo donax L

Abstract

The possible arsenic tolerance mechanisms were explored in Arundo donax L. under various supplied arsenic concentrations. The treatments included control (no metal) and five doses of arsenic trioxide i.e., 0, 50, 100, 300, 600 and 1000 μg L −1 As to A. donax. The phytoextraction ability of A. donax L. plants was assessed using both the translocation and bioaccumulation factors. The transpirates were collected to analyze the arsenic concentration volatilized along-with study of anatomical characteristics of the plant parts. In general, the arsenite and arsenate accumulation linearly increased in roots, shoot and leaves with the increasing supplied arsenic levels i.e., from 2.348, 2.775 and 3.25 μg g −1 at 50 μg L −1 to 50, 53.125 and 64.25 μg g −1 arsenite, at 1000 μg L −1, from 4.075, 5.425 and 13.56 μg g −1 at 50 μg L −1 to 71, 62.02 and 436.219 μg g −1 arsenate at 1000 μg L −1, respectively. The order of arsenic accumulation in A. donax L. was: solution As(III) < Root As(III) < Shoot As(III) < Leaf As(III) < Solution As(V) < Root As(V) < Shoot As(V) < Leaf As(V). The range of arsenic volatilization by A. donax L. was 7.2–22% at higher supplied arsenic (300–1000 μg L −1). Volatilization was an important mechanism to avoid toxic effects of arsenic by A. donax L. in addition to bioaccumulation.