The synthesis of high effective silicate materials for water basin protection from radioactive contamination
Application of surface and colloid chemistry modern approaches enable to purposefully increase sorptive capacity and selectivity of materials based on clay minerals by the porous structure features regulation and nature active sorptive sites changes. Large exchange capacity of the clay minerals is their important peculiarity, which is associated with well-developed heterovalent isomorphism and also by Si - OH and Al - OH functional groups on the side faces of alumosilicate structure packages. However, the most widespread use of layered silicates in water treatment technology is severely limited due to lack of selectivity and high dispersion in the natural state, making it impossible to create a continuous manufacturing processes.
Clay minerals surface modification by the cationic surfactants and large size metal polyhydroxy complexes makes possible formation of the desired porous structure and surface chemistry that provides increased selectivity to dangerous toxic compounds both in cationic and in anionic form (uranium, arsenic, chromium and others).
The basic physico-chemical peculiarities in production process of highly efficient silicate sorptive materials were established. These materials were synthesized by using large inorganic polyhydroxy complexes of metals with nanosized iron and based on increased sorption capacity and selectivity layered and layered-ribbon silicates.
Obtained columned (pilared) montmorillonites, which can be used as perspective sorbents for removal of heavy metals and radionuclides from the water environment, including high saline solutions and as effective catalysts. The structure and physicochemical properties of synthesized micro-mesoporous sorbents were investigated. It was shown that obtained materials effectively remove cationic, anionic forms and negatively charged complexes of inorganic toxicants in a wide pH range in contrast to the original mineral.
Composite sorption materials coated with a layer of nanosized Fe0 were synthesized and sorption-reduction mechanism for removing toxins in oxidized form (uranium, chromium) was established. Rheological properties of the nanodispersed reactive material suspension based on clay mineral palygorskite was investigated. The possibility of its use for treating groundwater contamination from uranium compounds was researched. The technological scheme of active sorption-reduction materials for groundwater purification against sewage pollution by uranium ore processing in the Eastern Mining and Processing Plant (Zhovty Vody city) was proposed. This technological scheme based on a cheap raw silica material (natural clays) and available reagents that do not require complex technological equipment.