Radiocesium reaction with illite and organic matter in marine sediment.
The mineralogical effect on the (137)Cs reaction with marine sediment has not been systematically studied yet, even though illite has been known to adsorb Cs preferentially on its frayed edge sites in a low Cs concentration. Ninety-three marine sediment samples were collected near Yangnam, Korea for quantitative X-ray-diffraction (XRD), gamma-ray, and total organic carbon (TOC) analysis. Illite content was in the range of 0-23 wt.% and those of (137)Cs and TOC were minimum detectable activity (MDA) approximately 7.19 Bq/kg-dry and approximately 3.32%, respectively. The illite content in the marine sediment showed a good relationship with the (137)Cs content (R(2)=0.69), but with an increase in the illite content, the relationship became less linear. This trend can be clearly shown in two groups of samples with different size fractions (< and >5Mdvarphi). For the samples of larger particle sizes (low contents of illite), the relationship is linear, but for the samples of the smaller particle sizes (high illite content) it is less linear with a decreased slope, indicating that increase in illite content does not significantly contribute to the fixation of (137)Cs in marine sediment. Rather, the TOC has a more linear relationship with (137)Cs content with no slope change in all particle size ranges. This may indicate that humic materials in marine sediment block the access of (137)Cs to the frayed edge site and reduces the adsorption of (137)Cs on illite and that the organic materials in marine sediment play more important roles in adsorbing Cs than illite.
Kim
Yeongkyoo
Y
Department of Geology, Kyungpook National University, Daegu 702-701, Republic of Korea. ygkim@knu.ac.kr
Cho
Sujin
S
Kang
Hee-Dong
HD
Kim
Wan
W
Lee
Heung-Rak
HR
Doh
Si-Hong
SH
Kim
Kangjoo
K
Yun
Sung-Gyu
SG
Kim
Do-Sung
DS
Jeong
Gi Young
GY
D000327:Adsorption; D002244:Carbon; D002588:Cesium Radioisotopes / Q000737:chemistry*; D019015:Geologic Sediments / Q000032:analysis / Q000737:chemistry*; D016014:Linear Models; D008903:Minerals / Q000737:chemistry*; D009792:Oceans and Seas; D010316:Particle Size; D014875:Water Pollutants, Radioactive / Q000032:analysis*
D002588:Cesium Radioisotopes; D008903:Minerals; D014875:Water Pollutants, Radioactive; C099089:illite; D002244:Carbon