Simplified measurement method for dissolved radio-Cs in litter and soil seepage water using copper-substituted Prussian blue

We developed a simple and rapid method for detecting dissolved radio-Cs in litter and/or soil seepage water using nonwoven fabrics impregnated with copper-substituted Prussian blue (Cu-NF). In laboratory and field experiments, litter and/or soil seepage water including dissolved radio-Cs were passed through traditional lysimeter systems combined with seven sheets of the Cu-NF. We then examined the recovery ratios of dissolved 137Cs in the Cu-NF. In the laboratory experiments with faster flow rates (11–2200 mm h−1), over 86% of the total dissolved 137Cs in litter seepage water was detected in the Cu-NF and over 82% of the collected 137Cs was present in the first three sheets. In the field experiments, 99% of the total dissolved 137Cs litter seepage water was collected in the Cu-NF and more than 96% of the collected 137Cs was present in the first three sheets. Furthermore, the recovery ratio of dissolved 137Cs increased with increasing installation Cu-NF length, probably because the packed soil in the Cu-NF lysimeter become more stable over time. Finally, because only the Cu-NF is measured, it is not necessary to undertake traditional measurement preparations such as filtration to remove particulate radio-Cs materials and evaporative concentration for low concentration of radio-Cs. As a result, we can save time and effort in measurement preparation by using the Cu-NF lysimeter method.