ARTYKUŁY I KOMUNIKATY NAUKOWE Szybkość uwalniania się 222Rn z wód podziemnych do atmosfery
Abstract
222Rn release rate from groundwater to the atmosphere.
A b s t r a c t. The authors conducted studies on the release rate of 222Rn from groundwater flowing out of a spring, from metamorphic reservoir rocks. This source gives rise to a stream about 205 m long. The activity concentration of 222Rn in the spring was about 700 Bq/dm3. We found that the rate of radon release into the atmosphere was best described by a third degree polynomial function. This means that the rate of radon release to the atmosphere decreases with distance from the spring. This process is accelerated by all zones of turbulent water flow in the stream – cascades, waterfalls, rapids, and similar zones. The decrease in the radon concentration to the values characteristic for surface waters in the investigated stream, which was a constant and minimum value, equal to about 1 Bq/dm3, took place at a distance of about 170–180 metres from the spring. With regard to the water flow path, flow time and the volume of water flowing through the cross-section of the tested stream, the exhalation coefficient of 222Rn from water to atmospheric air is 3.80 Bq/dm3/m, 1.51 Bq/dm3/s and 1.25 Bq/dm3/dm3, respctively. According to the authors, further research conducted in other springs occurring in other types of rocks and under different flow conditions (at different times of the year) will allow characterizing the dynamics of the process of 222Rn release from groundwater through surface waters into the atmosphere. Perhaps this process can be described with a universal mathematical function.
A b s t r a c t. The authors conducted studies on the release rate of 222Rn from groundwater flowing out of a spring, from metamorphic reservoir rocks. This source gives rise to a stream about 205 m long. The activity concentration of 222Rn in the spring was about 700 Bq/dm3. We found that the rate of radon release into the atmosphere was best described by a third degree polynomial function. This means that the rate of radon release to the atmosphere decreases with distance from the spring. This process is accelerated by all zones of turbulent water flow in the stream – cascades, waterfalls, rapids, and similar zones. The decrease in the radon concentration to the values characteristic for surface waters in the investigated stream, which was a constant and minimum value, equal to about 1 Bq/dm3, took place at a distance of about 170–180 metres from the spring. With regard to the water flow path, flow time and the volume of water flowing through the cross-section of the tested stream, the exhalation coefficient of 222Rn from water to atmospheric air is 3.80 Bq/dm3/m, 1.51 Bq/dm3/s and 1.25 Bq/dm3/dm3, respctively. According to the authors, further research conducted in other springs occurring in other types of rocks and under different flow conditions (at different times of the year) will allow characterizing the dynamics of the process of 222Rn release from groundwater through surface waters into the atmosphere. Perhaps this process can be described with a universal mathematical function.