Chemical evaluation of sand material sources for beach replenishment along the coast of the Gulf of Aqaba, Red Sea

摘要

Four potential borrow sites (sources of sand) for beach nourishment were selected at the Aqaba terraces and dredged offshore sand along the Jordanian coast of the Gulf of Aqaba, and at Al-Humaimah and Wadi Rum sand dunes north and northeast of Aqaba town. An elution test has been performed on the sand materials of these potential borrow sites to determine the levels of dissolved inorganic phosphorus and dissolved inorganic nitrogen that might be leached from the sand particles when they come into contact with seawater, and examine their suitability for beach replenishment works. The levels of total phosphorus, total nitrogen, organic matter and selected heavy metals were also measured in the sand materials after the elution test and compared with their levels in the same samples before elution and with their levels in the natural beach sand of the study area. The results of the tests show that the concentrations of the measured pollutants are low in the sand materials of the borrow sites, and the amounts of these pollutants that may reach the seawater of the Gulf of Aqaba, if quantities as large as 100,000 tons of the sand materials were used in beach nourishment projects, are very low when compared with their levels in seawater. The results of the tests, as well as organic matter and mud contents of the sand materials, indicate their suitability for use in beach nourishment. However, the Aqaba uplifted terraces would be the most suitable and the lowest cost source because they are common along the shores of the Gulf of Aqaba.