Scavenging process of 241Am on the continental margin of the East China Sea.

Abstract

The objectives of the present study were to determine the ²⁴¹Am, Pu and ²¹⁰Pb concentrations for settling particle and seafloor surface sediment samples collected on the continental margin in the East China Sea and to contribute to better understanding of the scavenging processes of ²⁴¹Am in the studied area. The ²⁴¹Am concentrations in settling particles tended to increase with trap depth. The tendency of the ²⁴¹Am concentration to increase was in good agreement with that of the ²¹⁰Pb concentration to increase. These results strongly suggested that there was a net accumulation of ²⁴¹Am and ²¹⁰Pb on the settling particles with depth, indicating active scavenging of these nuclides from seawater. A scenario for active scavenging could be strong adsorption by fine-grained clay particles, which underwent repeated resuspensions in the nepheloid layer and were flowing down the continental slope of the East China Sea.