Abstract
Groundwater was sampled in depth of about 50m for extraction of humic substances in the groundwater. The extraction and concentration of the humic substances were performed with synthetic adsorption resins. The extracted humic substances and reference humic substances were made a comparison in chemical property. Aquatic humic substances from Nordic Lake and non–aquatic Aldrich Co. humic acids were selected for the reference material. The unprocessed groundwater and the humic substances extracted from the groundwater were compared in UV-vis spectra, fluorescence spectra and the concentration ratio of humic acid and fulvic acid which were important in order to know characteristics of humic substances. Humic substances extracted from the groundwater were compared with Nordic humic substances in molecular weight distribution, IR spectra and NMR spectra from a viewpoint of complexation with radionuclides. This resulted that the extracted humic substances showed similar characteristics to humic substances in the groundwater, and that the extracted humic substances had similar characteristics to Nordic humic substances in containing acidic functional group which contributed to complexation and in americium complexation where americium complexed uniformly, independent of the molecular weight distribution as important characteristics for evaluation of effects on migration of radionuclides. These obtained results imply that employed method was applicable to extract dissolved humic substances from groundwater in a non-destructive manner and the dissolved humic substances occurring in groundwater in Japan are similar to aquatic Nordic humic substances, which are available to purchase at IHSS (International Humic Substances Society), in complexation behavior with some kind of metal ions.
