了解高碘酸盐种类在 H2O2/高碘酸盐过程中依赖于 pH 值的有机污染物降解中的重要性,Environmental Science & Technology

当前位置： X-MOL 学术 › Environ. Sci. Technol. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

了解高碘酸盐种类在 H2O2/高碘酸盐过程中依赖于 pH 值的有机污染物降解中的重要性
Environmental Science & Technology ( IF 10.8 ) Pub Date : 2022-07-07 , DOI: 10.1021/acs.est.2c02446
Tiansheng Chen ₁ , Yuankui Sun ₂ , Hongyu Dong ₂ , Jie Chen ₁ , Yanghai Yu ₁ , Zhimin Ao ₃ , Xiaohong Guan _{1,

2}

Affiliation

尽管基于高碘酸盐的高级氧化工艺已被证明在减少有机污染物方面是有效的，但不同高碘酸盐物种的活化特性仍不清楚。在此，通过强调 H ₄ IO ₆^{–的作用，我们重新研究了 pH 值对 H}₂ O ₂ /高碘酸盐工艺净化性能的影响。结果表明，将 pH 从 2.0 提高到 10.0 可以显着加快有机污染物的衰减速度，但会降低有机污染物的去除量。这种有机污染物降解的pH依赖性趋势与H2O ^·产量和高碘酸盐种类的变化非常吻合。具体来说，虽然¹ O在pH 9.0 可以检测到H 2 ，在所有测试的pH 水平下，H 2 O 2 /高碘酸盐过程中HO _·_被确定_为主要^的活性氧化物质。此外，有人提出只有 H ₄ IO ₆^-和 H ₂ I ₂ O ₁₀^{4 -}可以作为 HO ^·的前体。_{H 2} I ₂ O ₁₀^4–物质与 H ₂ O ₂反应的二级速率常数确定为~1199.5 M ^–1 s ^–1在 pH 9.0 时，比 H ₄ IO ₆^– （在 pH 3.0 时~2.2 M ^–1 s ^{–1 ）大两个数量级。}_{综上所述，提出了H 2} O ₂与不同高碘酸盐的反应途径。这些基本发现可以提高我们对基于高碘酸盐的高级氧化过程的理解。

"点击查看英文标题和摘要"

Understanding the Importance of Periodate Species in the pH-Dependent Degradation of Organic Contaminants in the H2O2/Periodate Process

Although periodate-based advanced oxidation processes have been proven to be efficient in abating organic contaminants, the activation properties of different periodate species remain largely unclear. Herein, by highlighting the role of H₄IO₆^–, we reinvestigated the pH effect on the decontamination performance of the H₂O₂/periodate process. Results revealed that elevating pH from 2.0 to 10.0 could markedly accelerate the rates of organic contaminant decay but decrease the amounts of organic contaminant removal. This pH-dependent trend of organic contaminant degradation corresponded well with the HO^· yield and the variation of periodate species. Specifically, although ¹O₂ could be detected at pH 9.0, HO^· was determined to be the major reactive oxidizing species in the H₂O₂/periodate process under all the tested pH levels. Furthermore, it was suggested that only H₄IO₆^– and H₂I₂O₁₀^4– could serve as the precursors of HO^·. The second-order rate constant for the reaction of H₂I₂O₁₀^4– species with H₂O₂ was determined to be ∼1199.5 M^–1 s^–1 at pH 9.0, which was two orders of magnitude greater than that of H₄IO₆^– (∼2.2 M^–1 s^–1 at pH 3.0). Taken together, the reaction pathways of H₂O₂ with different periodate species were proposed. These fundamental findings could improve our understanding of the periodate-based advanced oxidation processes.

更新日期：2022-07-07

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南