Investigation of Heavy Metals Accumulation in Plants Growing in Contaminated Soils (Case Study: Qazvin Province, Iran)
Authors
- Mahdieh Ebrahimi * 1
- Mohammad Jafari 2
- Gholam Reza Savaghebi 3
- Hossein Azarnivand 4
- Ali Tavili 5
- Fernando Madrid 6
Abstract
Environmental pollution with heavy metals is a global disaster that is related to
human activities. This study was conducted to determine the extent of heavy metals
accumulation by plant species in Lia industrial city (Qazvin, Iran) and to investigate the
remediative capacity of native plant species grown in the contaminated soils. Soil and
industrial wastewater sampling was done radially along transects with 300 m intervals
from exit point of wastewater at three sites. In each sampling point, along 100 m transects
within 5×2 m plots, the plant samples and soil samples were collected in depth of 0-20 cm
and 20-40 cm from rhizosphere zone. Concentration of copper, zinc and chromium in root
and shoot of 11 plant species, soil and wastewater were analyzed in three sits for
mentioned metals. Bio Concentration factors and translocation factor were determined to
ensure phytoremediation availability. Results showed that the concentrations of metals in
the soil and wastewater greatly exceeded the threshold limit values. The contents of metals
in soils ranged in the order of Cr>Zn>Cu and in wastewater were in the order of
Zn>Cr>Cu, respectively. Results showed that Scirpus maritimus L. and Phragmites
australis (Cav.) Trin. ex Steudel presented the highest accumulation of Zn, Cu and Cr in
their root tissues which were suitable for phytostabilization (with a high BCF couple with
low TF). The lowest extractable Zn (7.24 and 3.29 mgkg-1 for shoot and root respectively,
BCF=0.07) and extractable Cu (2.56 and 2.80 mgkg-1 for shoot and root respectively,
BCF=0.14) were related to Hordeum glaucum L. Moreover, the relatively lowest values of
Cr were measured for Taraxacum officinale L. Results indicated that the species, which
had low metal bioaccumulation in their roots and high TF, could play important roles for
removal of heavy metals through phytoextraction.
