3.6. Copper
Table 3 shows the Cu concentrations in wastewater samples
collected from in-let, all cells and out-let of the CW. The Cu
concentrations were ranged from 0.75 to 1.45 mg/L and its concentrations were exceeded the permissible limit (1.0 mg/L) in
the wastewater samples collected from in-let to cell-5. The
ANOVA analysis showed that the Cu concentrations in the out-let
wastewater samples were significantly lower (P< 0.01) than in-let
of the CW, indicating that the CW has effectively removed the Cu
from the wastewater. The Cu concentrations were ranged from 1.8
to 2.7 mg/kg in the sediment samples (Table 4). The Cu concentrations
were not regularly decreased as the distance increased
from in-let. These findings are in agreement with those reported
by Mays and Edwards (2001). The interaction between concentrations
and distance was significant for in-let and out-let
samples. This CW has shown 48.3% removal efficiency for Cu,
which is lower than the findings (98.8% and 99.3% for saline and
hypersaline water, respectively) of Kanagy et al. (2008). On other
hand, these findings are in agreement with those obtained from
CW treating highway runoff in the central Mediterranean region
(Terzakis et al., 2008).
Table 5 summarizes the plant uptake and accumulation of Cu
and its concentrations varied from species to species. Cu
concentrations ranged from 1.3 to 2.7 mg/kg in aerial tissues and
from 4.0 to 5.6 mg/kg in root tissues. These findings are comparable
with those reported in the literature (Campbell et al., 1988;
Bernard and Lauve, 1995; Lesage et al., 2007). The highest Cu
concentration was found in the P. australis followed by C. aquatilis
and T. latifolia. These plant species can be used for phytoremediation
of Cu contaminated wastewater. The RCF and ACF
values for different plant species are given in Table 6. Previous
studies have shown that the rhizofilteration is one of the main
mechanisms to remove Cu from wastewater