Regularities of radiation-catalytic system Ra-SiO3 in the process of water radiolysis

Full text: The main wastages of oil industry are ground waters which are enriched with natural radioisotopes. Efficient cleaning division of such radioisotopes is one of the actual problems. Sorbent production for radium division on the basis of natural zeolites and silicates is a more effective way. In this regard depending on the content of radium, radium silicates were synthesized. Its activities were tested in radiation-catalytic processes and play great role in the solution of environmental problems. Therefore, the purpose of this work is the investigation of kinetics of radiological water decomposition in contact with radium silicate with different radium content in it, which are equal to 260, 2500 and 6100 Bq/g, respectively. For the purpose to reveal influence of radium content in synthesized samples of radium silicate on water radiolysis, accumulation kinetics of molecular hydrogen in radiation catalytic decomposition of water have been investigated at room temperature T=300K, D=0.40 Gy/s and ρH2O=5 mg/cm3. From the slope of kinetic curves of linear area, generation rates and radiation-chemical yields of molecular hydrogen G(H2) have been determined which are equal to 0.012, 0.09 and 0.12 molecule/100 eV respectively. Besides, the values of radiation-chemical yield of molecular hydrogen calculated on energy which is absorbed by common system catalyst+ ads.H2O - Ggen.(H2) and adsorptive phase, have been determined. Thus, it is established that for all samples Gads. (H2) > Ggen.(H2), that indicates to the influence of silicate samples on molecular hydrogen treatment processes within water radiolysis in contact with them. Thus, obtained results on the study of radiation-catalytic activity of various radium-silicate samples in the process of water radiolysis (T=300K) show that radium silicate with A=6100 Bq/g possesses rather high catalytic activity. In order to identify the contribution of thermo -catalytic processes in the radiation-thermo-catalytic decomposition of water, accumulation kinetics of molecular hydrogen at thermo-catalytic and thermo-catalytic decomposition of water have been investigated with the presence of radium-silicate depending on the content of radium in the range of temperatures T=300-673 K. It has been established that radium-silicate depending on the content of radium at T≥573 K has thermo-catalytic activity in the water decomposition process. On the basis of these results, it is possible to make such assumption that there are various thermo-catalytic centers on the radium-silicate surface, which are activated at different temperatures. (author)