State Key Laboratory of Heavy Oil Processing, State Key Laboratory of Petroleum Pollution Control, China University of Petroleum-Beijing, Beijing 102249, China; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
State Key Laboratory of Heavy Oil Processing, State Key Laboratory of Petroleum Pollution Control, China University of Petroleum-Beijing, Beijing 102249, China.
Water Res. 2022 Jun 1;216:118315. doi: 10.1016/j.watres.2022.118315. Epub 2022 Mar 17.
Hydroxylamine (NHOH) has been verified to efficiently strengthen pollutants oxidation in Fe(II)/peroxydisulfate (PDS) and Fe(II)/HO systems. However, the different effects of hydroxylamine salts types were rarely recognized. Herein, the effects of two commonly used hydroxylamine salts (i.e. NHOH·HCl and (NHOH)·HSO) on oxidation kinetics and reactive species composition were compared in Fe(II)/PDS and Fe(II)/HO systems for the first time. Pseudo first order kinetics could only describe benzoic acid (BA) oxidation well in Fe(II)/NHOH/HO system, which was related to the different concentration changes of Fe(III) determined by [Formula: see text] . Hydroxylamine salts types influenced not kinetic rules, but reaction rates of target compounds. The empirical reaction rate constant of BA in Fe(II)/NHOH·HCl/PDS system was 141.5% of that in Fe(II)/(NHOH)·HSO/PDS system under the same concentration of NHOH (1.4 mM), while the apparent reaction rate constant in Fe(II)/NHOH·HCl/HO system was 68% of that in Fe(II)/(NHOH)·HSO/HO system. This opposite effect resulted from the differences in primary reactive species compositions and their interactions with Cl. Reactive species identification indicated that Cl would decrease the contribution of ferryl ion (Fe(IV)) and transform sulfate radical (SO) to hydroxyl radical (·OH) in Fe(II)/NHOH/PDS system, while it competitively consumed the only reactive species ·OH in Fe(II)/NHOH/HO system. This study highlights the importance of reductants types on strengthening Fenton oxidation and offers a reference for reasonable construction of the relevant systems.
羟胺（NHOH）已被证实可有效增强 Fe(II)/过一硫酸盐（PDS）和 Fe(II)/HO 体系中污染物的氧化。然而，羟胺盐类型的不同影响很少被认识到。本文首次比较了两种常用的羟胺盐（即 NHOH·HCl 和（NHOH）·HSO）在 Fe(II)/PDS 和 Fe(II)/HO 体系中对氧化动力学和反应性物质组成的影响。在 Fe(II)/NHOH/HO 体系中，只有准一级动力学可以很好地描述苯甲酸（BA）的氧化，这与[Formula: see text] 所决定的 Fe(III)浓度的不同变化有关。羟胺盐类型不仅影响动力学规律，还影响目标化合物的反应速率。在相同 NHOH（1.4 mM）浓度下，Fe(II)/NHOH·HCl/PDS 体系中 BA 的经验反应速率常数是 Fe(II)/(NHOH)·HSO/PDS 体系的 141.5%，而在 Fe(II)/NHOH·HCl/HO 体系中，表观反应速率常数是 Fe(II)/(NHOH)·HSO/HO 体系的 68%。这种相反的效果是由于主要反应性物质组成及其与 Cl 的相互作用的差异造成的。反应性物质鉴定表明，Cl 会降低高铁离子（Fe(IV)）的贡献，并将硫酸根自由基（SO）转化为羟基自由基（·OH）在 Fe(II)/NHOH/PDS 体系中，而在 Fe(II)/NHOH/HO 体系中，Cl 会竞争性地消耗唯一的反应性物质·OH。本研究强调了还原剂类型对强化芬顿氧化的重要性，为相关体系的合理构建提供了参考。
