|Budget Amount *help
¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1994 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1993 : ¥1,500,000 (Direct Cost : ¥1,500,000)
Humic and fulvic acids are the major organic constituents in natural waters. They interact with various toxic metal ions to form negatively charged humic complexes. The change of chemical forms often ffects on their geochemical behavior and biological effects. The humic substances are also known to be precursors of trihalomethanes formed during water treatment with chlorine. Therefore, the characterization of humic substances has been a topic of increasing research interest in geochemistry, environmental sciences and water treatment.
In the present work, the following main topics were studied in detail : (1) concentration of humic substances in large aqueous samples by continuous-flow coprecipitation-flotation, (2) determination of humic complexes in water by ICP-mass spectrometry after adsorption on indium-treated XAD-2 resin and DEAE-Sephadex A-25 anion exchanger, and (3) separation and determination of dissolved and particulate humic and fulvic acids in water. Further, it was found that anionic surfactants were very effective for the desorption of humic substances from XAD resins. The decomposition of copper (II) -humic complexes in salt water was also evaluated.