The effects of some chelating agents and
electricity on cadmium phytoextraction from a mine soil
were examined in pot culture of sunflower to achieve more
remediation efficiency. At the beginning of the flowering
stage, ethylene-diamine-tetra-acetic acid (EDTA) as a
chemical chelator, cow manure extract (CME) and poultry
manure extract (PME) as organic chelators were applied
(2 g kg
-1 soil) during irrigation. Seven days later,
Helianthus annuus
was negatively charged by inserting a
stainless steel needle in the lowest part of the stem with 10
and 30 V direct current electricity for 1 h each day for
14 days. Afterward, concentration of cadmium in roots and
shoots, cadmium translocation factor (TF), cadmium
uptake index (UI) and soil available (diethylene-triaminepenta-
acetic acid extractable) cadmium were measured.
Results indicated that EDTA reduced roots dry weight
while none of the roots and shoots was affected by other
chelating agents and by electrical treatment as well.
Highest concentration of cadmium in shoots was measured
in 10 V-control with no significant differences with 30 VPME
and 30 V-EDTA. Utilization of chelating agents did
not increase the cadmium TF and cadmium UI while
highest values for cadmium TF and cadmium UI were
observed in 10 and 30 V treatments, respectively. Available
cadmium in the soil near root system treated with 10
and 30 V was relatively lower compared with the soil far
from root system. Results of this experiment indicated that
charging the plant with direct current electricity ameliorated
the efficiency of cadmium phytoremediation.
