RESUMEN
Biochar (charcoal made from biomass in the pyrolysis process) has found broad application in agriculture. It helps to improve both the physical and chemical properties of soil through decontamination of heavy metals and pesticides. This work examines the potential for biochar application to improve the radiological condition of soil. We investigated the activity concentration of natural and anthropogenic radionuclides in soil samples collected from fields treated with various doses of biochar (in 1-100 Mg ha-1 ). In addition, we directly measured radon emission rate at the experimental fields. The analyses were performed using gamma spectrometry and an active method for radon emission using an AlphaGUARD instrument equipped with an accumulation box. The results of activity concentration assessments for six radionuclides, five natural and one anthropogenic, show that the only effect of biochar application into the soil is associated with the reduction of soil bulk density by this material. The radon emission rate increased by 6 mBq m-1 s-1 , on average, depending on the biochar dose (from 1 to 100 Mg ha-1 ). Our results demonstrate that application of biochar into soil kept without vegetation had a limited influence on the radioactivity in the environment.
Asunto(s)
Radiactividad , Contaminantes del Suelo/análisis , Carbón Orgánico , SueloRESUMEN
BACKGROUND: The calibration of the dosimetric instruments is a basis of safety of the people working with the ionization radiation. The necessity of calibration is especially important in the institutions where the open radioactive sources are used. The paper presents the abilities of CLOR's radiological protection instruments calibration facility and the important conclusions from calibrations results for group of instruments used in Nuclear Medicine Department in Poland. MATERIALS AND METHODS: The results for five types of instruments dedicated for dose rate as well as for contamination measurements were presented. Analyzes were based on the results presented at calibration certificated of chosen instruments. RESULTS: It has been shown that the calibration factor might fluctuate by 50% in period of one year for particular instrument as well as for more than 100% for two instruments of the same type. CONCLUSIONS: The presented results prove the importance of the calibration process and it is evidence that the calibration process of the radiation protection instruments should be performed periodically for the test of dose rate measurements as well as for contamination measurements abilities.