Removals of pesticides and pesticide transformation products during drinking water treatment processes and their impact on mutagen formation potential after chlorination

WATER RESEARCH

卷:138

Article

Matsushita, Taku¹  Morimoto, Ayako²  Kuriyama, Taisuke²  Matsumoto, Eisuke²  Matsui, Yoshihiko¹  Shirasaki, Nobutaka¹  Kondo, Takashi²  Takanashi, Hirokazu³  Kameya, Takashi⁴ 

[1] Hokkaido Univ, Fac Engn, N13W8, Sapporo, Hokkaido 0608628, Japan

[2] Hokkaido Univ, Grad Sch Engn, N13W8, Sapporo, Hokkaido 0608628, Japan

[3] Kagoshima Univ, Fac Sci & Engn, 1-21-40 Korimoto, Kagoshima 8900065, Japan

[4] Yokohama Natl Univ, Fac Environm & Informat Sci, 79-7 Tokiwadai, Yokohama, Kanagawa 2408501, Japan

关键词: Activated carbon adsorption;    Coagulation and sedimentation;    Disinfection by-product;    Ozonation;    Removal mechanisms;    Toxicity;   

DOI  :  10.1016/j.watres.2018.01.028

来源: Elsevier

【 摘 要 】

Removal efficiencies of 28 pesticide transformation products (TPs) and 15 parent pesticides during steps in drinking water treatment (coagulation-sedimentation, activated carbon adsorption, and ozonation) were estimated via laboratory-scale batch experiments, and the mechanisms underlying the removal at each step were elucidated via regression analyses. The removal via powdered activated carbon (PAC) treatment was correlated positively with the log K-ow at pH 7. The adjusted coefficient of determination (r(2)) increased when the energy level of the highest occupied molecular orbital (HOMO) was added as an explanatory variable, the suggestion being that adsorption onto PAC particles was largely governed by hydrophobic interactions. The residual error could be partly explained by pi-pi electron donor-acceptor interactions between the graphene surface of the PAC particles and the adsorbates. The removal via ozonation correlated positively with the energy level of the HOMO, probably because compounds with relatively high energy level HOMOs could more easily transfer an electron to the lowest unoccupied molecular orbital of ozone. Overall, the TPs tended to be more difficult to remove via PAC adsorption and ozonation than their parent pesticides. However, the TPs that were difficult to remove via PAC adsorption did not induce strong mutagenicity after chlorination, and the TPs that were associated with strong mutagenicity after chlorination could be removed via PAC adsorption. Therefore, PAC adsorption is hypothesized to be an effective method of treating drinking water to reduce the possibility of postchlorination mutagenicity associated with both TPs and their parent pesticides. (C) 2018 Elsevier Ltd. All rights reserved.

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