Phytomediation is an environmentally friendly green rehabilitation technology that is often
incorporated with an application to improve calcium peroxide and phytohormones required for the
growth of agricultural plants with the expectation to improve the effectiveness of plant rehabilitation.
This study mainly consists of two parts: (1) water culture experiment and (2) pot culture experiment. In
the water culture experiment, we attempt to understand the influence of the addition of calcium
peroxide, phytohormones (IAA and GA3) and a chelating agent on the growth of sunflower plants.
From the growth, we are then able to know the effectiveness of the addition of phytohormones.
However, in the pot culture experiment, when hormones and the chelating agent EDTA are introduced
to different plant groups at the same time, if the nutrition in the water required by plants is not
available, the addition of the hormone cannot negate the toxicity caused by EDTA. In terms of calcium
peroxide, due to quick release of oxygen in water, this study fails to apply calcium peroxide to the
water culture experiment. When the pot culture experiment is used to examine the influence of
hormones at different concentration levels on the growth of sunflowers, GA3 10-8M is reported to
have the optimaleffectiveness, followed by IAA 10-8M; IAA 10-12M has the lowest effectiveness.
According to an accumulation analysis of heavy metals at different levels, GA3 concentrates in
leaves to transport nutrition in soil to leaves. This result in an excellent TF value of 2.329G of GA3 than
1.845 of the control group indicating that the addition of the hormone and chelating agent to GA3
increases the TF value and the chelating agent is beneficial to the sunflower plant. If we examine
phytoattenuation ability, the one-month experiment was divided into three stages for ten days each.
The concentration level of heavy metals in the soil at each stage dropped continuously while that of the
control group decreased from 31.63 mg/kg to 23.96 mg/kg, GA3 from 32.09 mg/kg to 23.04 mg/kg
and EDTA from 30.65 mg/kg to 25.93 mg/kg indicating the quickest growth period of the sunflowers from
the formation of the bud to blossom. During the stage, the quick upward transportation of nutrition results
in quick accumulation of heavy metals; the accumulated speed of heavy metals is found higher than that of
directly planted plants. This study shows an improvement in the effectiveness of the addition of
hormones on plant extraction and when rehabilitation is incorporated with sunflowers with the
beginning bud formation, better treatment effectiveness can be reached
T. Y. Yeh
Department of Civil and Environmental Engineering, National University of Kaohsiung, Taiwan.