Sorption and desorption of radiocesium on red earth and its solid components: relative contribution and hysteresis.
The relative contributions of organic matter and iron oxides to the Cs+ sorption on red earth were investigated by using the batch technique and selective extraction methods. The sorption and desorption isotherms and the distribution coefficients of Cs+ on the untreated red earth and the three treated soils to remove organic matter, iron oxides and organic matter plus iron oxides were determined at 20 degrees C, pH 6.3+/-0.2, in the presence of 0.01 mol/l CaCl2. It was found that all the isotherms are linear in the Cs+ concentration range used here, that the sorption desorption hysteresis on the red earth actually occurs, and besides the clay minerals, the organic matter present in the red earth is a significant trap of Cs+ and is responsible for the hysteresis instead of the iron oxides.
Xiangke
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W
Radiochemistry Laboratory, College of Chemistry and Chemical Engineering, Lanzhou University, People's Republic of China.
Wenming
D
D
Zhi
L
L
Du Jinzhou
Zuyi
T
T
D000327:Adsorption; D002588:Cesium Radioisotopes / Q000032:analysis* / Q000737:chemistry; D012987:Soil / Q000032:analysis*; D012990:Soil Pollutants, Radioactive / Q000032:analysis*
D002588:Cesium Radioisotopes; D012987:Soil; D012990:Soil Pollutants, Radioactive