A promising ozone-based advanced oxidation process for effective generation of hydroxyl radicals in acidic solution
A promising ozone-based advanced oxidation process for effective generation of hydroxyl radicals in acidic solution
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DOI：
10.1016/j.seppur.2015.07.062
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发表时间：
2015-09
影响因子：
8.6
通讯作者：
Yao Chen;Ruofan Peng;Tongdong Shen;S. Tong;Chun’an Ma
中科院分区：
文献类型：
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作者：
Yao Chen;Ruofan Peng;Tongdong Shen;S. Tong;Chun’an Ma
在pH = 3.0的条件下，考察了钛硅分子筛TS-1对H2 O2/O3氧化的影响，并以对臭氧呈惰性的乙酸为目标有机物。由于H2 O2在酸性溶液中不可能发生脱质子反应，H2 O2/O3对乙酸的去除率可以忽略不计（30 min内为5.6%）。而TS-1钛硅分子筛的加入可显著提高H_2O_2/O_3的氧化效率（30 min时为29%）。研究了H2 O2浓度、TS-1浓度、臭氧投加速率和pH值等因素对TS-1/H2 O2/O3氧化HAc效率的影响，结果表明TS-1/H2 O2/O3对HAc的降解是由反应物（包括臭氧和HAc）向TS-1表面的转移控制的。添加叔丁醇和二甲基亚砜（DMSO）的试验均证实了该过程中产生羟基自由基。羟基自由基的产生速率可以通过调节H2 O2的浓度来控制。羟基自由基的产生机制可能是TS-1与H_2O_2相互作用产生的活性氧物种（包括Ti（IV）-超氧化物和Ti（IV）-过氧化氢/过氧化物）与溶解的臭氧反应。研究结果对含难降解臭氧惰性有机物酸性废水的有效预处理具有重要意义。
The oxidative efficiency of H2O2/O3in the presence or absence of titanium silicalite of TS-1 was investigated at pH value of 3.0, in which acetic acid was selected as the target organic compound owing to its inert to ozone. The removal rate of acetic acid by H2O2/O3was negligible (5.6% in 30 min) because of the impossible deprotonation reaction of H2O2in acidic solution. However, addition of titanium silicalite of TS-1 could greatly improve the oxidative efficiency of H2O2/O3(29% in 30 min). The results of effects of different parameters such as concentration of H2O2, concentration of TS-1, rate of ozone input, and pH value, on the oxidative efficiency of TS-1/H2O2/O3showed that the degradation of HAc by TS-1/H2O2/O3was controlled by the transfers of reactants (including ozone and HAc) to the surface of TS-1. The tests of addition of tert-butyl alcohol and dimethyl sulfoxide (DMSO) both confirmed generation of hydroxyl radicals in this process. The rate of generation of hydroxyl radicals could be controlled by adjusting the concentration of H2O2. The mechanism for generation of hydroxyl radicals might be the reaction of some reactive oxygen species (including Ti(IV)-superoxide and Ti(IV)-hydroperoxide/peroxide), which resulted from the interaction of TS-1 with H2O2, with dissolved ozone. The results are of significance for the effective pretreatment of acidic wastewater containing refractory ozone-inert organic matter.