2003 Fiscal Year Final Research Report Summary
MX as an Index of Tocicity of Drinking Water in Distribution Systems
| Project/Area Number |
14350288
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Civil and environmental engineering
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
ITOH Sadahiko Kyoto Univ., Grad.School of Eng., Professor, 工学研究科, 教授 (10184657)
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| Project Period (FY) |
2002 – 2003
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| Keywords | chromosomal aberration test / transformation test / MX / disinfection by-products / chlorination |
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| Research Abstract |
It is impossible to determine and measure all substances in drinking water. The bioassay results used as comprehensive water quality indicators are expected to be utilized for water quality management. When disinfection by-products are used as indicators of drinking water quality, they should be chosen properly in water treatment process and water distribution. In the water distribution systems, MX was supposed to be a suitable indicator. In this study, MX was found to be unstable in water due to the hydrolysis and the decomposition by chlorination. Also, it was found that the decay rate of MX in aqueous phase strongly depends on pH. The decay rate of MX is much faster in alkali region. Furthermore, MX decayed faster when higher chlorine was present. The activities inducing chromosomal aberrations and transformations of MX showed similar tendency. The activity inducing chromosomal aberrations and the activity inducing transformations measured by non-two-stage assay in Lake Biwa increased rapidly after the addition of chlorine, and then began to decrease gradually. MX seemed to be an appropriate indicator qualitatively and quantitatively for the toxicity of chlorinated water in distribution system. However, it was necessary to take the residual chlorine into consideration.
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Research Products
(4 results)
