International Journal of Marine Science, 2017, Vol.7, No.35, 353-360
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In particulate phase, the concentrations in the exchangeable phase ranged from (954.1 µg/g dry weight) at station 5
to (2396.5 µg/g dry weight) at station 4. Significant differences (P<0.01) were found among the concentrations at
different stations. In the residual phase of the particulate ranged from (325.2 µg/g dry weight) at station 5 to (423.3
µg/g dry weight) at station 1. Non-significant differences (P>0.05) were found among the residual concentrations at
different stations.
Nickel concentration in the dissolved phase ranged from (8.39 µg/L) at station 5 to (10.45 µg/L) at station 1 (Table
1). In particulate phase, the concentrations in the exchangeable phase ranged from (81.99 µg/g dry weight) at station
5 to (135.17 µg/g dry weight) at station 3. The nickel concentrations in the residual phase of particulate ranged from
(126.49 µg/g dry weight) at station 4 to (194.83 µg/g dry weight) at station 1. Non-significant differences (P>0.05)
were found among the concentrations of nickel (as dissolve or as particulate) at different stations.
The concentrations of lead in dissolved phase ranged from (40.91 µg/L) at station 3 to (46.55 µg/L
)
at station 2
(Table 1). Non-significant differences (P>0.05) were found among the dissolved concentrations at different stations.
In particulate phase, the concentrations in the exchangeable phase ranged from (144.6 µg/g dry weight) at station 5
to (321.1 µg/g dry weight) at station 4. Significant differences (P<0.05) were found among the concentrations at
different stations, while in the residual phase of particulate ranged from (159.8 µg/g dry weight) at station to (509.3
µg/g dry weight) at station 4. Non-significant differences (P>0.05) were found among the residual concentrations at
different stations.
The concentrations of zinc in dissolved phase ranged from (5.43µg/L) at station 5 to (9.65 µg/L) at station 4 (Table
1). Non-significant differences (P>0.05) were found among the dissolved concentrations at different stations. In
particulate phase, the concentrations in the exchangeable phase ranged from (107.0 µg/g dry weight) at station 5 to
(385.3 µg/g dry weight) at station 2. Significant differences (P<0.01) were found among the concentrations at
different stations, whereas in the residual phase of particulate ranged from (127.4 µg/g dry weight) at station 5 to
(254.2 µg/g dry weight) at station 4 and non-significant differences (P>0.05) were found among the concentrations
at different stations.
In the present study the concentrations of Pb, Cd and Fe in dissolved phase at most stations exceeded the highest
permissible limits of drinking water, and this finding was in agreement with Al-Saffie (2005) who found elevated in
Pb concentrations at Shatt Al-Arab river and Hassan (2007) who found elevation in Cd and Pb concentrations at
Shatt Al-Arab river. The concentrations of other metals (Ni, Mn, Cu, and Zn) were below the permissible limits of
drinking water according to the WHO (2011) (Table 2). The present finding was in agreement with Mastoi et al.
(2008) who found that the main source of high level of Cd in water is the runoff from the agricultural fields rich in
chemical fertilizers. The spatial elevated concentrations could be related to land-based point source discharges
caused by rapid urbanization and economic development in Basrah city center, this finding was in agreement with
Al-Hejuje (1997) and Zhang et al. (2009), or may be due to a wide range of anthropogenic impacts linked to
variations in population density, wastewater discharges and industrial activities. The river is extensively used for
washing vehicle and the wastewater is drained back into the river, the vehicle emission which can travel for a long
distance from the source of emission by atmospheric transport, traffic sources, and cities are the main sources of
contaminations of heavy metals in the river (Song et al., 2010; Manoj et al., 2012). The fluctuation in the
concentrations of heavy metals could be attributed to the interactions between multi factors that affect the
concentrations of dissolved metals, such as the unequal amount s of sewage discharged, the phytoplankton and
aquatic plants densities which absorbed or adsorbed the ionic metals, the sand storms occurring, and the fuel burn
emissions specially during Summer as a result of electrical power generation machines that released large amounts
of metals, especially lead compounds, into the river.
The mean concentrations of all the studied heavy metals in particulate phase were higher than those in dissolved
phase. This finding was in agreement with Al-Khafaji (1996); Al-Hejuje (1997) and Hassan et al. (2010). Most of
heavy metals in particulate phase positively correlated with those in dissolved phase and this could be attributed to
