Radiochemistry最新文献

The Cauvery and Palar are two significant rivers in Tamil Nadu, India. These rivers produce electricity and water for drinking and irrigation and provide sand for building construction. Uranium, thorium, and potassium are examples of naturally occurring radioactive elements that have been studied for Cauvery and Palar river soil. The radiation levels and possible human exposure were measured using specialized equipment. The annual radiation dose and the amount of radiation that the body absorbs both indoors and outdoors were other factors examined in the study. Several risk indicators were also evaluated to determine the possible health risks associated with this radiation. According to the study, most of radioactive levels in the rivers fall within the usual range compared to worldwide averages. It indicates that there is no substantial radioactive risk in the Cauvery River (except from site number 20). The radiation levels in site no. 6 of Palar River are three times higher than the global average, indicating a slight increase in radiation levels. Metals including copper, zinc, nickel, chromium, and iron were also examined. The correlations between these elements in the riverbeds with magnetic characteristics, radiation exposure levels, and possible dangers was also studied. The comprehension of the distribution of radiation and its relationship to other environmental factors was aided by this analysis.

The influence of microorganisms collected from observation wells near the conserved liquid radioactive waste (RW) repository, B-2 reservoir, of the Siberian Chemical Combine on the immobilization of uranium, plutonium, and neptunium on pyrite, siderite, and goethite was studied. The results of laboratory experiments and thermodynamic simulation data show that the microbial transformation of iron-bearing minerals leads to an increase in the immobilization of actinides due to the appearance of new biogenic iron oxide/hydroxide/carbonate and iron sulfide mineral phases.

The effect of the extractant content on the efficiency of ytterbium and lutetium separation from nitric acid solutions was studied for a sorbent made by impregnating Prefilter resin with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester. It is shown that the distribution ratios of Yb and Lu and their retention coefficients in the column increase as the extractant content increases. At the nitric acid concentration of 1.5 M, the effective separation of Yb and Lu is provided by the sorbent containing at least 40 wt % extractant. When separating equal amounts of Yb and Lu (0.5 mg each) in a column with 10 cm³ of sorbent at an elution rate of 1 mL/min and a temperature of 50°C, the yield of lutetium in the purified fraction exceeds 85%, providing Yb relative content in the Lu fraction less than 0.14% (1 atom of Yb per 700 atoms of Lu).

Sorption of neodymium, lanthanum and thorium fluorides from melt under column conditions using AG-3 activated carbon at a temperature of 650°C was studied for the first time. The known eutectic mixture of alkali metal fluorides LiF–NaF–KF was employed as a melt. A special setup for studying the sorption process under column conditions was developed and created for the experiments. Three main sections were identified in the process of sorption of neodymium and lanthanum fluorides: the sorption front formation zone, sorption and breakthrough zones. It was shown that under the considered conditions, purification of thorium fluoride from lanthanum fluoride is possible. The sorption capacity towards lanthanum fluoride more than 5 mg/g at its maximum reached and depended on the melt flow rate through the activated carbon zone. Thorium fluoride was not sorbed by activated carbon under the studied conditions.

A brief hydrographic description of the Techa River and main radionuclide-contaminated water bodies (WBs) located in the surveillance zone of the Mayak Production Association is made. Along with the Mayak Production Association, two other independent institutions monitor the radioactive contamination of these WBs. The results of monitoring the contamination of surface WBs, obtained by all the participating institutions in 2023, are presented in comparison with the results obtained in 2021–2022. With respect to the majority of the parameters monitored, the radioactive contamination of WBs is considerably lower than the interference level. In 2023, the discharge of radionuclides (⁹⁰Sr) into the open hydrographic network of the Techa River was 0.24% of the established limit of permissible discharges.

The results of an experiment to verify a complex technology for isolation of ¹⁷⁷Lu from an irradiated 1-g ytterbium target are presented. The main components of the experimental installation, which is mounted in a research hot cell, are described. These components include the extraction and separation of lutetium and ytterbium, the evaporation and preconcentration of ¹⁷⁷Lu, and its chromatographic purification. The feasibility of obtaining a pharmaceutical substance no carrier added lutetium-177 trichloride that meets the standards set by the European Pharmacopoeia has been confirmed.

The availability of tap water sources is an important aspect of public health. Radon concentrations in water are an important source of water pollution. The water quality in seven Karbala sites in Iraq was evaluated using five parameters: temperature (T), total dissolved solids (TDS), pH, electrical conductivity (EC), and salinity (S). The ²²²Rn levels in the tap water samples were studied using a CR-39 detector. The concentrations of radon gas in the tap water samples were less than the accepted international limit of 11.1 Bq L^–1, and the annual effective dose was less than the required international value of 1 mSv year^–1. Therefore, the tap water used in all areas of the Karbala governorate is safe in terms of its ²²²Rn content. Water temperatures in Karbala City are below the Canadian Council of Ministers of the Environment (CCME) standard limit of 15°C, except for the Northern Drainage (Al-Shariea Site), where the temperature is above the limit because of the different intended sampling and the hot Iraqi environment. The TDS difference measured in tap water is greater than the water level limit of 500 mg L^–1 set by the World Health Organization (WHO) and CCME, and the measured pH values were within the standard ranges, 6.5–8.5 and 6.5–9, defined by the WHO and CCME, respectively. All water samples had electrical conductivities above the WHO requirement of 1000 S cm^–1 but below the CCME standard of 1500 S cm^–1. The content of primary cations (Ca²⁺, Mg²⁺, Na⁺, and K⁺) and heavy metals (zinc, copper, nickel, lead, and cadmium) was determined by flame atomic absorption spectroscopy (FAAS),. Primary cations follow the order Na⁺ > K⁺ > Ca²⁺ > Mg²⁺, and heavy metal ions, the order Zn²⁺ > Pb²⁺ > Cu²⁺ > Cd²⁺ > Ni²⁺. The average readings for Pb²⁺ and K⁺ were greater than the optional safe levels recommended by the CCME and WHO.