Peculiarities of the Distribution of Aluminum among Its Coexisting Forms in Surface Water Bodies of Various Types

Abstract

Results of the study of the coexisting forms of aluminum in surface water bodies of different types (reservoirs, lakes, and rivers) are discussed in the paper. It has been found that the distribution of Al(III) among suspended and dissolved forms depends not only on the content of suspended matter in the water, but also on its nature (mineral or organic suspended matter). Relationship between the mass of suspended matter and the content of aluminum in the composition of suspended matter was not established. The concentration of Alsusp increased in the case of a predominance of mineral suspended matter, which was observed on the example of river waters. The dissolved forms of aluminum were represented mainly by its complex compounds with dissolved organic matter of various chemical nature and molecular mass. The content of aluminum labile fraction varied over a wide range and increased from spring until summer. Either anionic, or neutral compounds predominate among the complexes of Al(III) with dissolved organic matter, which depends on the peculiarities of the component composition of organic matter in water bodies. The complexes of Al(III) with dissolved organic matter are formed mainly at the expense of the compounds with a rather low molecular mass (≤ 2 kDa).