Acrylic fibers coated with copper hexacyanoferrate to determine 137Cs activity in coastal seawater of Vietnam

A method employing 137 Cs sorption to copper hexacyanoferrate (Cu 2 [Fe(CN) 6 ])-coated fibers for determining 137 Cs activity in seawater is presented in this paper. The Cu 2 [Fe(CN) 6 ]-coated fibers were packed into a PVC cartridge and used to treat 300 L of seawater, exhibiting a 137 Cs sorption efficiency of above 99%. The Cu 2 [Fe(CN) 6 ]-fiber samples containing 137 Cs were subsequently dried and placed into a 500 mL Marinelli beaker to determine the activity concentrations by gamma spectrometry. This method was applied to seawater of the Phuoc Dinh and Vinh Hai coastal areas in Ninh Thuan province, Vietnam. The activity concentrations of 137 Cs in the surveyed areas ranged from 1.14 to 1.44 Bq/m 3 . The activities of 137 Cs in the seawater samples of this work were compared with those observed in seawater on the coasts of Vietnam and other countries along the South China Sea.