Formy występowania kadmu, ołowiu i cynku we współczesnych osadach aluwialnych Polski
Abstract
FORMS OF OCCURRENCE OF CADMIUM, LEAD AND ZINC IN RECENT ALLUVIAL DEPOSITS OF POLAND
Summary
In alluvial sediments concentrates a considerable part of heavy metals that are mobilized due to the industrial activity. Because of a possibility of renewed mobilization and migration of heavy metals from the sediments it is important to know in what forms these elements are fixed in alluvial sediments. Therefore, selective extraction was used for 48 samples of alluvial sediments were taken from contaminated rivers from the entire area of Poland. The five-stage extraction made possible to determine a contribution of fixation of studied elements: 1) clay minerals, 2) carbonate minerals, 3) Fe and Mn oxides and hydroxides, 4) organic matter and sulfides, 5) other components. The contribution of fixation of Cd, Pb and Zn varies to a great extent, as evidenced by the cadmium fixation that in some cases is related to clay minerals (60% in Ślęża River deposits in Wroclaw), and to carbonate minerals (> 60% in Vistula River deposits in Cracow) or organic matter and sulfides (> 60% in Jeziorka River in Konstancin) in other cases. It was established that in sediments characterized by very high contents of Cd, Pb or Zn, the elements occur mostly in forms that are easily made mobile: exchangeable, bound to carbonate and to Fe and Mn oxides, due to changes in physico-chemical conditions. It was observed that a great part of the elements occurs in the most easy mobilized forms that are related to clay minerals, e.g. in some samples of alluvial sediments hundreds or even> 1000 ppm of Zn occur in the forms.
Summary
In alluvial sediments concentrates a considerable part of heavy metals that are mobilized due to the industrial activity. Because of a possibility of renewed mobilization and migration of heavy metals from the sediments it is important to know in what forms these elements are fixed in alluvial sediments. Therefore, selective extraction was used for 48 samples of alluvial sediments were taken from contaminated rivers from the entire area of Poland. The five-stage extraction made possible to determine a contribution of fixation of studied elements: 1) clay minerals, 2) carbonate minerals, 3) Fe and Mn oxides and hydroxides, 4) organic matter and sulfides, 5) other components. The contribution of fixation of Cd, Pb and Zn varies to a great extent, as evidenced by the cadmium fixation that in some cases is related to clay minerals (60% in Ślęża River deposits in Wroclaw), and to carbonate minerals (> 60% in Vistula River deposits in Cracow) or organic matter and sulfides (> 60% in Jeziorka River in Konstancin) in other cases. It was established that in sediments characterized by very high contents of Cd, Pb or Zn, the elements occur mostly in forms that are easily made mobile: exchangeable, bound to carbonate and to Fe and Mn oxides, due to changes in physico-chemical conditions. It was observed that a great part of the elements occurs in the most easy mobilized forms that are related to clay minerals, e.g. in some samples of alluvial sediments hundreds or even> 1000 ppm of Zn occur in the forms.