Content and Distribution of Heavy Metals among Their Dissolved and Suspended Forms in the Water of the Rivers of the Tisza River Basin

摘要

Results of the study of the content of the dissolved and suspended forms of some metals in the water of the rivers of the Tisza River basin in 2015-2016 are given in the paper. It has been found that in the water of the studied rivers the total concentration of Cd, Cu, Pb, Zn, Ni, and Cr varied over a wide range and accounted for 0.03-5.90, 0.9-18.4, 0.7-16.5, 2.3-52.2, 0.3-21.7, and 0.1-8.0 μg/L. The concentration of the dissolved form of metals (most bioavailable to hydrobionts) accounted for 0.04-0.61, 0.06-11.5, 0.5-8.6, 1.0-36.3, 0.1-15.3, and 0.03-5.9 μg/L, respectively. Previously the concentration of Cu, Pb, and Zn was higher, especially after the accident at the metal mining enterprises, when their content in the dissolved form accounted for 30-110, 16-24, and 40-120 μg/L. It has been found that Cd and Cr migrate mainly in the composition of suspended matter, the contribution of which to their total content accounts for 40.0-81.7 and 25.5-64.7%. Other studied metals migrate mainly in the dissolved state. A relative content of slightly absorbed fraction of Cd, Cu, Pb, Zn, Ni, and Cr in the composition of suspended form was on the average 53.3, 23.2, 29.2, 28.3,22.0, and 12.2%. The contribution of the studied metals to the composition of mineral particles lattice on the average accounted for 18.7, 62.9, 49.4, 40.2, 30.8, and 55.0%, respectively. Preliminary investigations have shown that the studied metals, with the exception of copper, occurring in the dissolved form are registered mainly in the composition of neutral fraction (52-83%). A relative content of copper in the composition of anionic fraction is about 55% of its dissolved form.