نوع مقاله : مقاله پژوهشی
نویسندگان
گروه فیزیک، دانشکده علوم پایه، دانشگاه اراک، اراک، ایران
کلیدواژهها
عنوان مقاله English
نویسندگان English
In this study, the radioactivity concentration in the soil and sediments of the Galougah River on the southern side of the Miankaleh Wetland in northern Iran, which originates from the northern heights of the Alborz Mountains, as well as the bed wetland sediments of the estuary of that river was studied. The mean specific activities of 226Ra, 232Th, 40K, and 137Cs in the sediments of the Galougah River respectively were 32.12, 32.47, 339.81, and 2.53 Bq/kg, in the soil along the river respectively were 34.20, 38.28, 505.94, and 6.89 Bq/kg, and in the wetland bed sediments near the mouth of the Galougah River respectively were 20.88, 21.22, 287.90, and 2.75 Bq/kg obtained. The average radioactivity concentration in the river sediments was lower than that of the surrounding soil, indicating that radioactive salts were washed away and transported to downstream areas by the river water flow. The high concentration of 40K in the downstream part of the river could be due to contamination from potassium fertilizers used for agricultural purposes in that area. The distribution pattern of 226Ra in the Miankaleh Wetland near the outlet of the Galougah River indicates the rapid deposition of this radionuclide immediately after leaving the river mouth, which settles in sandy-clay sediments. A similar distribution pattern was obtained for 232Th and 40K in the wetland, indicating a similar influence on the diffusion of these radionuclides from the water currents of the wetland, as well as a similar absorption of thorium and potassium salts by the sediments. The distribution pattern of 137Cs in the wetland indicates that this radionuclide is deposited in far from the river outlet in the calm area of the wetland, which is due to the high mobility of 137Cs, which causes it to be transported to distant locations by water flow.
کلیدواژهها English
