A layered double hydroxide (LDH) was successfully deposited on a glass-bead filter (GBF) disk, and the product changed color from white to orange after flowing methyl orange aqueous solution. These results clearly indicated the formation of an LDH-coated GBF disk, i.e., an anion-adsorbed inorganic filter disk.

Radioactively contaminated soils sampled at Fukushima (Japan) underwent microwave treatment to remove cesium ions. An aqueous suspension (20 mL) containing 5.0 g of the soil (7.2×10⁵ Bq/kg) and one of three chemical reagents was sealed in a Teflon vessel (4.0 cm i.d.×5.0 cm). The effects of the following three reagents were examined: 3.0 M Mg(NO₃)₂, 6.5 M NH₄F/HF, and 1.5 M H₂SO₄. The vessel was irradiated with microwaves at 800 W for 3 min. After the vessel was cooled to room temperature, the contents were removed and centrifuged, and the radioactivity of the solid precipitate was measured. The elemental composition of the filtrate was determined using ICP-MS. The XRD patterns of the solid precipitates were recorded before and after the treatment. Results indicated that: (i) in the radioactive Cs⁺ ions leaching experiment with 3.0 M Mg(NO₃)₂ from a reference saponite, 85% ¹³⁷Cs⁺ ions were desorbed after 3 min of microwave irradiation, indicating the effectiveness of the microwave treatment for radioactively contaminated soils, (ii) less than 5% of the radioactive Cs⁺ (or ¹³⁷Cs⁺) ions were eliminated through ion-exchange with 3.0 M Mg(NO₃)₂; (iii) more than 90% of the ¹³⁷Cs⁺ ions were effectively eliminated with 6.5 M NH₄F/HF via dissolution of silica; (iv) approximately 70% of the ¹³⁷Cs⁺ ions were eliminated with 1.5 M H₂SO₄ via dissolution of alumina. These results demonstrated that ¹³⁷Cs⁺ ions in the soil were fixed firmly in clay minerals (possibly weathered biotite) and could be removed only when their adsorbing structures were disrupted.

This article was retracted.

In this study, a high-temperature gas permeation measurement apparatus that can be used at temperatures above 100°C was assembled. The apparatus uses a helium leak detector and is characterized with a wide measurement range. After evaluating the soundness of the apparatus, the He permeation of polyimide films with a coating layer consisting of clay nanoplates was successfully measured in the range of 40–160°C. The activation energy of the gas permeation was evaluated from an Arrhenius plot of the He permeability, and it showed that the apparatus is a powerful tool regarding the development of gas shielding materials at high temperatures.