水中の共存物質が<I>N</I>-ニトロソジメチルアミンの紫外線分解と再生成に及ぼす影響  [in Japanese] Effects of Coexisting Matters on Photodegradation and Reformation of <I>N</I>-Nitrosodimethylamine  [in Japanese]

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Abstract

<I>N</I>-ニトロソジメチルアミン(NDMA)は,水のオゾン処理や塩素消毒処理による発がん性の副生成物で,紫外線分解される。分解産物はNDMAの前駆物質であり,紫外線分解処理後の塩素添加でNDMAを再生成する可能性が懸念される。本研究では,100 ng·L<SUP>-1</SUP>のNDMA溶液に共存物質として有機物と硝酸イオンを水道水質基準以下の濃度で添加し,共存物質がNDMAの紫外線分解特性とその後の生成能に及ぼす影響を調べた。分解速度は紫外線光源によって異なり,エキシマ,低圧,中圧紫外線ランプでそれぞれ8.7,2.7,2.3 cm<SUP>2</SUP>·J<SUP>-1</SUP>であった。分解は,共存物質によって阻害され,エキシマ,低圧,中圧ランプでそれぞれ約40~90%,7~50%,20~60%低下した。紫外線照射後の溶液にクロラミンを添加した場合のNDMA生成能の増加は,共存物質の濃度によらず最大5 ng·L<SUP>-1</SUP>以下であった。

<I>N</I>-nitrosodimethylamine (NDMA) is a probable human carcinogen formed as a by-product of the chlorination and ozonation of water. It is photodegradable by UV irradiation, but its reformation is suspected when chlorine is added to UV-irradiated water. In this research, the photodegradation of NDMA by irradiation with excimer, low-pressure (LP), and medium-pressure (MP) UV lamps was investigated using NDMA solutions with an initial concentration of 100 ng·L<SUP>-1</SUP>. To examine the effects of coexisting matters on the photodegradation and reformation of NDMA, Suwannee River NOM and/or nitrate was added to the test solutions at concentrations below the drinking water standard in Japan. The rates of photodegradation by using the excimer, LP, and MP UV lamps were 8.7, 2.7, and 2.3 cm<SUP>2</SUP>·J<SUP>-1</SUP>, respectively. The photodegradation rate was reduced by coexisting matters at about 40-90%, 7-50%, and 20-60% for the excimer, LP, and MP UV lamp, respectively. The increase in NDMA formation potential by chloramination was 5 ng·L<SUP>-1</SUP> or less, regardless of the coexisting matters.

Journal

  • Journal of Japan Society on Water Environment

    Journal of Japan Society on Water Environment 36(6), 175-181, 2013

    Japan Society on Water Environment

Codes

  • NII Article ID (NAID)
    130003384507
  • NII NACSIS-CAT ID (NCID)
    AN10372439
  • Text Lang
    JPN
  • ISSN
    0916-8958
  • NDL Article ID
    025074439
  • NDL Call No.
    Z16-1045
  • Data Source
    NDL  J-STAGE 
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