Modeling phototransformation reactions in surface water bodies: 2,4-dichloro-6-nitrophenol as a case study.
Modeling phototransformation reactions in surface water bodies: 2,4-dichloro-6-nitrophenol as a case study.
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DOI：
10.1021/es102458n
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发表时间：
2011
影响因子：
11.4
通讯作者：
P. Maddigapu;M. Minella;D. Vione;V. Maurino;C. Minero
中科院分区：
文献类型：
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作者：
P. Maddigapu;M. Minella;D. Vione;V. Maurino;C. Minero
阴离子形式的2，4-二氯-6-硝基苯酚在紫外光照射下的直接光解量子产率为(4.53±0.78)×10(-6)，二级反应速率常数为(2.8±0.3)×10(-1)M(-1)S(-1)与·OH，(3.7±1.4)×10(9)M(-1)S(-1)与(1)O(2)，和(1.36±0.0 9)×10(8)M(-1)S(-1)，其激发三重态为2-苯酚-2-磺酸盐，可作为地表水中具有光活性的溶解有机物的替代物。DCNP与碳酸根的反应活性也可以忽略不计。将数据嵌入地表水光化学模型表明，直接光解以及与·OH和(1)O(2)的反应将是DCNP的主要光转化过程，其中·OH在贫有机水体中占主导地位，(1)O(2)在富有机水体中占主导地位。模型结果与法国南部罗纳河三角洲DCNP的现场数据吻合较好，其中(1)O(2)将是底物光转化的主要反应物种。
The anionic form of 2,4-dichloro-6-nitrophenol (DCNP), which prevails in surface waters over the undissociated one, has a direct photolysis quantum yield of (4.53 ± 0.78) × 10(-6) under UVA irradiation and second-order reaction rate constants of (2.8 ± 0.3) × 10(9) M(-1) s(-1) with •OH, (3.7 ± 1.4) × 10(9) M(-1) s(-1) with (1)O(2), and (1.36 ± 0.09) × 10(8) M(-1) s(-1) with the excited triplet state of anthraquinone-2-sulfonate, adopted as a proxy for the photoactive dissolved organic compounds in surface waters. DCNP also shows negligible reactivity with the carbonate radical. Insertion of the data into a model of surface water photochemistry indicates that the direct photolysis and the reactions with •OH and (1)O(2) would be the main phototransformation processes of DCNP, with •OH prevailing in organic-poor and (1)O(2) in organic-rich waters. The model results compare well with the field data of DCNP in the Rhône river delta (Southern France), where (1)O(2) would be the main reactive species for the phototransformation of the substrate.