Complexing–precipitating geochemical barriers

Abstract

New types of geochemical barriers on which chemical elements are immobilized as a result of combined complex formation and precipitation of barely soluble mineral phases are examined. A significant concentration of major components (Fe, Al) forming more stable complexes than an immobilized component X in the material is a necessary condition for this type of geochemical barriers. Filtration of the solution through a geochemical barrier is accompanied by substitution of X in the complex with a major component. As a result, the activity of X in the free state increases, and one barely soluble mineral phase or another of the component X precipitates when the state of saturation is achieved.