Monitoring safety of japanese mackerel

Monitoring of the concentration of toxic elements, N-nitrosamines, pesticides, polychlorinated biphenyls and cesium and strontium radionuclides in the raw muscle tissue of the Japanese mackerel putin 2014-2019 was carried out. It was found that the investigated safety indicators of Japanese mackerel caught in the South Kuril fishing zone and in the Pacific subzone of the North Kuril fishing zone in 2014 – 2019 correspond to modern quality requirements. It is noted that Japanese mackerel can be used as a valuable raw material for the production of food products.

Modern Sorption Materials for Cesium and Strontium Radionuclide Extraction from Liquid Radioactive Waste

The paper describes the main types of sorption materials used to remove cesium and strontium radionuclides from low-level and intermediate-level liquid radioactive waste (LRW). It mainly focuses on sorbents produced at an industrial or pilot scale in Russia. Based on a developed standardized technique, it presents the experimental values for 137Cs and 90Sr distribution coefficients (Kd ) accounting for various types of sorbents. The study demonstrates that based on the developed technique, sorption characteristics of various types of sorption materials can be compared in an unbiased manner and most effective sorbents can be reasonably selected to treat liquid radioactive waste of various salt and radionuclide composition.

Strontium in Phosphate-Modified Calcium Aluminate Cement

Cements have been used to encapsulate low and intermediate level radioactive wastes. Here, phosphate-modified calcium aluminate (CAP) cement is explored as an encapsulant for strontium radioanuclide-containing wastes. Electron microscopy indicates strontium chloride, used in place of strontium radionuclides, increases porosity in CAP possibly due to increased viscosity of CAP cement during mixing. X-ray diffraction analysis detects formation of halite phase suggesting strontium chloride reacts with cement to form sodium chloride not usually detected in CAP systems as well as formation of an amorphous phase in CAP cement when thermally treated at 90°C.

Treatment of Surface Waters from Technogenic Radionuclides with Modified Granulated Green Earth

The method of obtaining new sorbents on a natural carrier is described. It is shown that surface modification of granulated green earth with iron-potassium ferrocyanide and iron hydroxide compounds allows synthesizing materials with higher specificity and sorption capacity with respect to cesium and strontium radionuclides, respectively. The resulting sorbents are suitable for water treatment in both static and dynamic modes. The maintaining of good hydrodynamic characteristics after conducting experiments under dynamic conditions confirms the possibility of using them as filter loading in water purification and water treatment. Radionuclide-saturated sorbents can be considered as reliable matrices for immobilizing radionuclides. The promising areas for the use of modified green earth are the treatment of radionuclide-contaminated drinking water and the rehabilitation of natural water bodies in radioactively contaminated areas.

Seawater purification from cesium and strontium radionuclides

The article deals with the study of sorption (under batch conditions) of cesium and strontium radionuclides from sea water with ferrocyanidic sorbents based on hydrated titanium and zirconium dioxides (Т-35, NPF-HTD), glauconite and clinoptilolite natural aluminum silicates (NPF-G, NPF-C), zirconium phosphate (Т-3А), modified hydrated zirconium dioxide (Т-3К), and manganese dioxide based on hydrated titanium dioxide (MD-HTD). We have obtained the sorption isotherms, defined the cesium and strontium distribution coefficients. Dependences of the cesium distribution coefficient by the sorbents in seawater saline content have been obtained. The authors recommend NPF-G and NPF-HTD sorbents for treatment of liquid radioactive waste based on seawater with various salt content. Coefficients of the cesium distribution between solid and liquid phases were 1,0∙105 and 1,0∙104 mg/l, respectively, even at solutions with the salt content of 100 g/l. In the process of strontium sorption from seawater, the strontium distribution coefficients do not exceed 1,9·102 ml/g, this is connected with big proportion (34±7 %) of stable colloidal forms of strontium in the simulated seawater.