DISTRIBUTION OF BORON FRACTIONS IN MEDITERRANEAN SEA SEDIMENTS (EL-MAX AND ABU-QIR BAYS), EGYPT

摘要

The aim of this study is to understand the geochemi-cal forms of boron (B). It was fractionated by sequential extraction technique in 21 surface sediment samples collected from 2 regions; El-Mex Bay and Abu Qir Bay, during April 2007. The amount of total B and the different fractions were determined by colorimetric Curcumin method. The values of contamination factor (Cf) of B in the sediments at the 2 regions revealed that it was highly enriched in B, from 2 to 3-fold. The ranges and the mean concentrations of B (μg/g) in both regions for the different fractions were 28.35-65.03 (42.68) for hot water fraction; 5.73-41.66 (17.75) for exchangeable; 0.38-97.64 (25.88) for specific extraction (0.05 M KH_2PO_4); 11.08-38.60 (18.78) bound to Fe-Mn oxides; 26.75-71.52(41.31) in the organic fraction, and 1.53-48.25(28.82) as residual. The relative proportion of B extracted was in the following order: hot water > organically bound > residual form > specific extraction > oxides bound > exchangeable. The present study showed that the sum of the 5 fractions (non-residual fractions) is generally more than 50 % of total B content, which is relatively easily dissolved with the release of occluded elements. These fractions may be potentially toxic for uptake by organisms.