The 10th Int. Conf. on Hydroscience and Engineering (ICHE-2012), Nov. 4 – Nov. 7, Orlando, USA
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INTERACTION BETWEEN THE PHOSPHORUS
AND SUSPENDED SEDIMENT IN KUWAIT BAY
Eqbal Al-Enezi1;Nouf Alomani1, Majid Wadi1 and Ahmed. Al-Khabbaz 1
ABSTRACT
Phosphorus plays an important role in eutrophication of the marine environment and aquatic systems.
Suspended sediment may act both as a source or sink of phosphorus to the water depending on the
physico- chemical factors, such as pH, salinity, DO and phosphorus concentration in the water. The
adsorption /desorption processes of phosphorus by the suspended sediment were studied to understand
the phosphorus behaviour in the Kuwait Bay. The dominant mineralogical composition of the suspended
sediment is quartzitic calcareous sandy silt (Khalaf et al. 1985), which is mostly derived from dust
fallout in the Kuwait Bay waters. Also, Al-Ghadban and A. El-Sammak, 2005 studied the source and
composition of suspended sediment in the Kuwait Bay, and they found that high concentration of quartz
and feldspar, and lower carbonate contents towards the eastern part of the bay. They noted that the Shatt
Al-Arab, in a major supplier of suspended load into the bay. Also there are many studies have been
stated that the Shatt Al-Arab may be a major supplier of suspended sediments in the northern Arabian
Gulf, such as Al- Bakri et al., 1984; Al-Ghadban et al., 1999; Khan, 2002. Substantial quantities of
inorganic phosphorus are released from suspended sediment of the Kuwait Bay, over periods of few
hours. The aim of this study is to defining the physical and biogeochemical processes influencing the
transport of phosphorus in the suspended sediment-water interface. In this study, experiments were
carried out to determine the equilibrium of phosphorus between suspended sediment and water in
Kuwait Bay under a range of variances such as (pH, salinity, DO and temperature). Ten water and
suspended sediment samples were collected from the Kuwait Bay during the neap and spring tides. The
phosphorus desorption from suspended sediment was determined by the easy exchangeable phosphorus
(MgCl2 extractable) methods (Ruttenberg, 1992) and the maximum phosphorus adsorption by suspended
sediment was measured (Smith et al. 2006) methods.
1
Environmental Science Department, Kuwait Institute for Scientific Research, P.O. Box 24885, Safat 13109,
Kuwait. eenezi@kisr.edu.kw
The 10th Int. Conf. on Hydroscience and Engineering (ICHE-2012), Nov. 4 – Nov. 7, Orlando, USA
1
The adsorbed phosphorus concentrations in the suspended sediment range vary between 0.1 to 0.5 mg/l
and desorption from suspended sediment into the water range between 0.07 to 0.4 mg/l. This difference
was attributed to the chemical composition of the suspended sediment. The range of adsorption
concentration varies according to water quality. A positive correlation was found between adsorbed
phosphorus and concentration of suspended sediment in the water column. A numerical model such as
(Delft 3D) was applied to simulate the effect of the sediment-adsorbed phosphorus to the total
phosphorus distribution in the Kuwait Bay. The modelling result indicated that the high concentration of
suspended sediment have adverse impact on water quality, especially in western part of Kuwait Bay due
to low water circulation in this part in the Bay and other.
Figure 1 Locations of suspended sediments samples in the Kuwait Bay
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