Change of Physico-chemical Properties of Dissolved Organic Matters Induced by Ultraviolet Irradiation and Photocatalyst

摘要

Physico-chemical properties of dissolved organic matters in river water and ultraviolet irradiated water with or without photocatalyst are examined. Molecular size, hydrophilicity, and adsorbability to solid phase extraction cartridge are identified by 260nm absorbance detection of HPLC, high performance liquid chromatography. Organic constituents were separated into two peaks by HPLC; one consists of low molecular size substances (below 1000) which had very low adsorbability to solid phase extraction cartridge; the other consisted of higher adsorbability and higher molecular size, whose 260nm absorbance was degraded by ultraviolet irradiation with TiO_2 photocatalyst. Irradiation of 254nm ultraviolet light (UVC) induced mutagenicity in Salmonella typhymurium TA100 without S9 metabolization. 80 μg·l~(-1) of formaldehyde was detected over two--hour UVC irradiation.