Cesium adsorption from aqueous solutions onto Japanese oak charcoal II: effects of metal ions eluted from the charcoal

Abstract

The major metal elements contained in Japanese oak (Quercus serrata Thunb. and/or Quercus crispula Blume) charcoal (OC) and activated charcoal (AC) were identified by X-ray fluorescence spectroscopy. The eluted amounts of sodium, potassium, magnesium, and calcium ions from OC and AC were measured using ion chromatography. We attempted to demineralize OC and AC by water-washing, and then determined the eluted amounts of the four metal ions from the washed OC and AC. The effects of the water-washing on the adsorption of cesium ions onto OC and AC were investigated with respect to 2.50 × 10−4 and 2.50 × 10−5 mol/L aqueous cesium chloride solutions. Remarkably, the washing improved the adsorption ability of OC for cesium ions in solutions whose initial cesium chloride concentration was 2.50 × 10−5 mol/L, although such effects were not so noticeable in solutions whose initial cesium chloride concentration was 2.50 × 10−4 mol/L.