Minor and trace elements in Dead Sea water

Abstract

The average concentration of several metals in six water profiles taken from the Dead Sea are: Sr = 308−330 mg/l; Li = 17−21 mg/l; Mn = 3.1−8.0 mg/l; Cu = 300−500 μg/l; Zn = 500 μg/l; Fe = 10−15 μg/l; Ni = 20−25 μg/l; Co = 8 μg/l, Cd = 8−10 μg/l, Pb = 120−300 μg/l; I = 80−120 μg/l and U = 1.5−2.5 μg/l. The mechanisms which govern the behavior of metals in the Dead Sea are: (a) incorporation into authigenic carbonates and sulfides in the sediment (Sr, Zn, Cd, Fe); (b) formation of soluble salts or soluble chloridic complexes (Li, Mn, Pb); and (c) removal due to reduction and formation of sparingly soluble compounds (U). High concentrations of Mn (up to 135 mg/l) were found in interstitial water separated from the sediments. Several sets of experiments on interstitial water from the Dead Sea and marine sediments indicate that the high concentration of Mn is not due to the formation of high-molecular-weight organic complex but rather to the formation of inorganic complexes similar to that of the alkali and alkaline-earth metals. In the Dead Sea the evidence strongly points towards chloridic complexes.