Geochemical Behavior of Ferric Hydroxide Nanodispersion Under the Influence of Weak Magnetic Fields

Abstract

The change of geochemical properties of ferric hydroxide nanoparticles under the influence of a weak magnetic field was investigated. Ferric hydroxide nanoparticles formed as a result of the interaction of iron-containing minerals with natural aqueous solutions are of importance for geochemical processes, especially hypergenesis, sedimentation, and soil formation. The hydrolysis of ferric chloride in hot water (t = 70-75°С) was used to obtain ferric hydroxide nanoparticles under laboratory conditions. The nanodispersion (colloidal solution) was exposed to a weak pulsed magnetic field. The spectrophotometric properties of the colloidal solution of ferric hydroxide were determined using an SF-46 spectrophotometer in the wavelength range of 320-610 nm. The size of colloidal particles was calculated by a method based on the theory of Rayleigh light scattering. The size of colloidal particles depended on the exposure duration of a pulsed magnetic field on the colloidal solution. The size of colloidal particles was due to a change in the magnitude of the diffuse ionic atmosphere under the influence of a pulsed magnetic field. The kinetic stability of the colloidal solution was evaluated by the coagulation threshold, which was determined visually by the appearance of the turbidity of ferric hydroxide colloid when adding NaCl solution. The kinetic stability of a colloidal system was determined by the size of colloidal particles. These results can be used to better understand certain hypergenesis, sedimentation, and soil formation processes.

Magnetite-ferrocyanide-copper sorbents for recovery of cesium ions from low-activity liquid radioactive waters

“…6,7 Among natural minerals, clinoptilolite, vermiculite, and montmorillonite we most often used for radionuclide sorption, but their main disadvantage is a relatively low sorption capacity. 1,4 The most effective sorbents for cesium extraction are ferrocyanide sorbents [8][9][10][11] and sorbents based on magnetite nanoparticles [12][13][14] and complex magnetite-silicate-zeolite sorbents 15,16 which are quite promising for the selective removal of cesium (up to 80 %) and strontium (up to 90 %) radionuclides from contaminated waters by magnetic separation. A particularly promising technology for radioactive water purification is the application of Plasma Sorb technology, which uses multi-stage purification not only by physical methods, but also by complex sorbents, including ferrocyanides, iron nanoparticles and other components.…”