Chromium accumulation and its effects on other mineral elements in Amaranthus viridis L.

Chromium accumulation and its effects on other mineral elements in Amaranthus viridis L. were investigated using inductively coupled plasma atomic emission spectrometry (ICP-AES) and resin adsorption. The aim was to understand why A. viridis can grow well in soils heavily contaminated by Cr, what the forms of Cr in soils and residues are, and what effects Cr has on the distribution of Mn. Fe, Cu and Zn in the plant. The results indicated that A. viridis is not a hyperaccumulator, although it can grow well in soil containing a high concentration of Cr. The Cr concentration in plant tissues from a contaminated site was about 11 times higher than in those from an uncontaminated site. At both the contaminated and uncontaminated sites, Cr was accumulated primarily in its shoots, and in roots in much lower concentrations. The levels of Cr in A. viridis tissues were as follows: leaf > root > stem. Cr occurred predominantly as Cr(III). There was very little Cr(VI) in the polluted soil where A. viridis grew close to a waste heap discarded by a chromium(VI) production factory. The possible mechanisms for Cr accumulation of A. viridis and the effects of Cr on uptake and accumulation of the other mineral elements in A. viridis are briefly discussed.