Page 199 - Plant-Based Remediation Processes

10 Phytostabilization as Soil Remediation Strategy 191

a 700 a
Total Cu in plant tissues (mg kg -1 ) 400 e b cd b d b e bc a ab
600
500

300
200
b
100
b
ab
0
HIGH
LOW
b 2800 Control Cu Cu/Zn Cu/Cr Cu Cu/Zn Cu/Cr
Total Zn in plant tissues (mg kg -1 ) 1600 c g Zn Cu/Zn Zn/Cr ab b Cu/Zn Zn/Cr
Shoots-Leaves
Roots
2400
2000
a
ab
1200
800
a
bc
bc
c
400
c
d
f
e
0
Zn
Total Cr in plant tissues (mg kg -1 ) 120 a b c b d b f a b b e
c 200 Control LOW b HIGH
160
b
80
40
0
g
HIGH
Control Cr Cu/Cr Zn/Cr Cr Cu/Cr Zn/Cr
LOW
Soil Treatment
Fig. 10.4 Total concentration and distribution of heavy metals in shoots and roots of Sesbania
virgata plants. Vertical bars represent standard deviations. The means followed by the same latter
(a–e) were not significantly different at p < 0.05

had a pattern of variation different from that of Cu. At high doses, the concentration
in shoots/leaves was higher than at low doses only with Cu (Fig. 10.4b; Table 10.1).
In contrast, Cr concentration was higher in roots of S. virgata in the individual
treatment at high doses. A possible explanation for this trend is that the sorption
capacity of each metallic cation of the mixture might decrease in competitive
processes (Flogeac et al. 2007) (Fig. 10.4c; Table 10.1).
The transfer factor (TF) determined for S. virgata tissues showed a similar
behavior for Cu, Zn, and Cr. Generally, in all treatments, TF values obtained for