Photocatalytic mechanisms of 2,4-dinitroanisole degradation in water deciphered by C and N dual-element isotope fractionation

JOURNAL OF HAZARDOUS MATERIALS

卷:411

Article

Wang, Chunlei¹  Fuller, Mark E.²  Heraty, Linnea J.¹  Hatzinger, Paul B.²  Sturchio, Neil C.¹ 

[1] Univ Delaware, Dept Earth Sci, Newark, DE 19716 USA

[2] Aptim Fed Serv LLC, Lawrenceville, NJ 08648 USA

关键词: 2,4-dinitroanisole;    UV photolysis;    Photosensitizer;    C-13 and N-15 dual-isotopic fractionations;   

DOI  :  10.1016/j.jhazmat.2021.125109

来源: Elsevier

【 摘 要 】

In surface water environments, photodegradation may be an important process for the natural attenuation of 2,4-dinitroanisole (DNAN). Understanding the photolysis and photocatalysis mechanisms of DNAN is difficult because the photosensitivity of nitro groups and the behavior of DNAN as a potential photosensitizer are unclear in aqueous solutions. Here, we investigate the degradation mechanisms of DNAN under UV-A (lambda similar to 350 nm) and UV-C (lambda similar to 254 nm) irradiation in a photolysis reactor where aqueous solution was continuously recycled through a UV-irradiated volume from a non-irradiated external reservoir. By tracking C and N isotopic fractionation in DNAN and its reaction products, we observed normal C-13 fractionation (epsilon(C) = -3.34 parts per thousand) and inverse N-15 fractionation (epsilon(N) = +12.30 parts per thousand) under UV-A (lambda similar to 350 nm) irradiation, in contrast to inverse C-13 fractionation (epsilon(C) = +1.45 parts per thousand) and normal N-15 fractionation (epsilon(N) = -3.79 parts per thousand) under UV-C (lambda similar to 254 nm) irradiation. These results indicate that DNAN can act as a photosensitizer and may follow a product-to-parent reversion mechanism in surface water environments. The data also indicate that photocatalytic degradation of DNAN in aqueous systems can be monitored via C and N stable isotope analysis.

【 授权许可】

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