Sorbents Based on Polyacrylonitrile Fiber for Complex Recovery of Artificial 137Cs and Natural Radionuclides from Natural Media

Sorbents based on polyacrylonitrile fiber, containing ferrocyanides of transition metals and manganese oxides (CoMn-PAN and FeMn-PAN) or iron(III) hydroxide (CoFe-PAN) in their structure were obtained, as confirmed by the results of X-ray diffraction and energy-dispersive analyses. The selectivity of the obtained sorbents was investigated, along with their ability to sorb Cs, Ba (as an analog of Ra), P, and Be from various natural media, including river water and seawater with varying salinity of 18.2 and 33.8 parts per thousand. The data show that the sorbents are universal for the recovery of artificial Cs-137 and natural radionuclides from the natural environments, including complex salt composition (seawater). Researching the obtained sorbents during marine expeditions confirmed the efficiency of the obtained materials based on transition metal ferrocyanides and manganese oxides (CoMn-PAN and FeMn-PAN) for the sorption of Cs-137, Be-7, Pb-210, Po-210, Ra-226, Ra-228, and Th-234. Additionally, the sorbent based on transition metal ferrocyanides and iron(III) hydroxide (CoFe-PAN) was effective for the sorption of Cs-137, Be-7, P-32, P-33, Pb-210, Po-210, and Th-234. Based on the obtained results, methods for comprehensively determining artificial Cs-137 and natural radionuclides using these sorbents were developed.