Static Adsorption of Cesium Ions on Kaolin/Vermiculite and Dynamic Adsorption/Desorption Using the Electrokinetic Process

Abstract

The interactions between cesium ions and two kinds of 2 : 1 clay minerals (kaolin and vermiculite) were investigated under batch conditions and dynamic equilibrium using the electrokinetic (EK) process. The adsorption capacities of kaolin and vermiculite were 1.2 and 18.8 mg/g, respectively, at pH 6 after 24 h in the batch system. Because the basal spacing of kaolin is 0.93 nm, Cs ions cannot enter the interlayers. On the other hand, the basal spacing of vermiculite is 1.01 nm, and vermiculite can adsorb Cs ions in the interlayers. Four kinds of model soils with di erent ratios of vermiculite to kaolin were prepared by mixing these two types of clay minerals, and the migration behaviors of Cs ions in these soils on the application of the EK process were determined. The Cs ion migration e ciency decreased with an increase in vermiculite content. The content of vermiculite in the soil was an important factor determining the migration behavior of Cs ions under the dynamic equilibrium conditions produced by the EK process. The applications and limitations of the EK process for the removal of cesium from contaminated soil are discussed.

Enhancement Effect of Humic Acid on Removal of Lead from Soil by Electrokinetic Process

“…This material includes pyrophyllite (one of the clay mineral) and quartz. 12 In this paper, white clay was expressed as 'pyrophyllite'. Pb(NO3)2, NaOH and HCl were purchased from Wako Pure Chemical Industries, Ltd. HA was purchased from Sigma Aldrich Co.…”

“…[3][4][5][6][7] Recently, the applications of the EK process to the soil contaminated with radioactive Cs have been performed. [8][9][10][11][12] To enhance the removal efficiency of heavy metals from soil, the strong inorganic acid or artificial chelating reagent such as EDTA were used. 13,14 However, the use of these substances may cause newly the secondary pollution.…”

Evaluation of Removal Behavior of Cesium in Contaminated Soil Based on Speciation Analysis

“…These studies have been performed using various methods, experimental conditions, and soil samples. [4][5][6][7][8][9][10] However, the diversity of the decontamination studies makes it difficult to compare the effectiveness of these treatment methods. In particular, when different soil samples were used, different results were obtained, even under similar treatment condition.…”