Strong Enhancement on Fenton Oxidation by Addition of Hydroxylamine to Accelerate the Ferric and Ferrous Iron Cycles
Strong Enhancement on Fenton Oxidation by Addition of Hydroxylamine to Accelerate the Ferric and Ferrous Iron Cycles
复制标题
DOI：
10.1021/es2002748
复制
发表时间：
2011-05-01
影响因子：
11.4
通讯作者：
Xie, Pengchao
中科院分区：
文献类型：
--
作者：
Chen, Liwei;Ma, Jun;Xie, Pengchao
Fenton体系通过Fe(II)与H_2O_2的反应产生具有高氧化电位的活性物种，如羟基自由基(HO中心点)或铁基。然而，Fenton-HA存在的一些缺点限制了它的广泛应用，包括Fe(III)的积累和较窄的pH范围等。本研究的目的是提出一种更有效的Fenton-HA体系，其特点是将Fenton体系与常用的还原剂羟胺(NH_2OH)相结合，以苯甲酸(BA)为探针剂。Fenton试剂中NH_2OH的存在加速了Fe(III)/Fe(II)氧化还原循环，使Fe(II)的回收率相对稳定，从而提高了准一级反应速率，使有效pH范围扩大到5.7。结果表明，Fenton-HA体系以Ho中心点机制为主，且Ho中心点的生成速度比经典Fenton体系快得多，生成的Ho中心点数量也比经典Fenton体系多。此外，在Fenton-HA体系中，NH_2OH的主要最终产物是NO_3~-和N_2O。
The Fenton system generates reactive species with high oxidation potential such as hydroxyl radicals (HO center dot) or ferryl via the reaction between Fe (II) and H2O2. However, a number of drawbacks limit its widespread application including the accumulation of Fe (III) and the narrow pH range limits, etc. The aim of this study is to propose a much more efficient Fenton-HA system which is characterized by combining Fenton system with hydroxylamine (NH2OH), a common reducing agent, to relieve the aforementioned drawbacks, with benzoic acid (BA) as the probe reagent. The presence of NH2OH in Fenton's reagent accelerated the Fe (III)/Fe (II) redox cycles, leading to relatively steady Fe (II) recovery, thus, increased the pseudo first-order reaction rates and expanded the effective pH range up to 5.7. The HO center dot mechanism was confirmed to be dominating in the Fenton-HA system, and the generation of HO center dot was much faster and the amount of HO center dot formed was higher than that in the classical Fenton system. Furthermore, the major end products of NH2OH in Fenton-HA system were supposed to be NO3- and N2O.