Quality of bottom surface sediments at an industrial site on the southern coast of the gulf of Aqaba, Jordan

الملخص EN

Bottom surface sediments were collected twice a year over a period of six years (1996-2001) at three different depths (10, 20 and 30 m) from six stations in front of an Industrial Complex site (IC) that harbored a thermal power station, a phosphate fertilizers complex, a potash export terminal and a mixed fertilizers plant.

Samples were analyzed for grain size, ignition loss, organic carbon, hydrogen sulfide, total nitrogen and total phosphorus contents.

Investigated sediments were mainly medium sands with main grain size between 125 and 500 jam.

Sediments showed no significant differences with respect to the measured variables neither with time nor with sites.

At all six stations, sediments were well Dxygenated as indicated from the low hydrogen sulfide concentrations (less than 0.8 mg kg"1).

Ignition loss values were much higher than the arganic carbon contents.

This can be attributed to calcium carbonate decomposition and oxidation of the possibly existing sulfur upon ignition, Fluctuation in total phosphorus and nitrogen concentrations from one sampling event to another were clear but irregular.

This is best explained by the relatively low residence time of organic matter in marine sediments, especially in warm environments such as Aqaba, In comparison with previous records, results of the present investigation ndicate that the quality of the sediment at the Industrial Site is comparable with that in other sites along the northern Gulf of Aqaba.

In conclusion sediments at the Industrial Site appear to have attained steady itate equilibrium where basic environmental parameters are nsignificantly modified from the baseline values on the Jordanian coast >f the Gulf of Aqaba.