Experimental Fundamentals of the Colloid Hydrogeochemistry of Continental Runoff

Abstract

The authors have previously developed the separation principles of filtering water samples rich in colloids into size fractions by the method of cascade filtration and by studying the migration of trace elements with them. Data acquired by studying the migration of a great number (forty to sixty) elements and organic matter (OM) of riverine runoff show that the method is highly promising for the separation of size fractions in search for stable geochemical associations of trace elements variably adsorbed on suspensions. Filtration with the application of seven to ten filter nominals, with the systematically decreasing pore diameter, was proven to be an efficient method for studying trace-element complexation with dispersed organic matter (DOM) in water bodies. However, the application of membrane filters made of organic materials of various nature (Nylon 6, lavsan, modified nitrocellulose, etc.) places certain constraints, which are caused not so much by the adsorption activity of the membranes but mostly by the rapid clogging of pores in the membranes with the gel-like amorphous precipitate. The paper is devoted to analysis of the newly suggested method of continuous gel-filtration.