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In Situ-Generated Reactive Oxygen Species in Precharged Titania and Tungsten Trioxide Composite Catalyst Membrane Filters: Application to As(III) Oxidation in the Absence of Irradiation.
Environmental Science & Technology ( IF 10.8 ) Pub Date : 2020-06-16 , DOI: 10.1021/acs.est.0c01550
Jiyeon Park 1 , Jonghun Lim 2 , Yiseul Park 3 , Dong Suk Han 4 , Ho Kyong Shon 5 , Michael R Hoffmann 2 , Hyunwoong Park 1
Affiliation  

This study demonstrates that in situ-generated reactive oxygen species (ROSs) in prephotocharged TiO2 and WO3 (TW) composite particle-embedded inorganic membrane filters oxidize arsenite (As(III)) into arsenate (As(V)) without any auxiliary chemical oxidants under ambient conditions in the dark. TW membrane filters have been charged with UV or simulated sunlight and subsequently transferred to a once-through flow-type system. The charged TW filters can transfer the stored electrons to dissolved O2, producing ROSs that mediate As(III) oxidation in the dark. Dramatic inhibition of As(V) production with O2 removal or addition of ROS quenchers indicates an ROS-mediated As(III) oxidation mechanism. Electron paramagnetic spectroscopic analysis has confirmed the formation of the HO2/O2•– pair in the dark. The WO3 fraction in the TW filter significantly influences the performance of the As(III) oxidation, while As(V) production is enhanced with increasing charging time and solution pH. The As(III) oxidation is terminated when the singly charged TW filter is fully discharged; however, recharging of TW recovers the catalytic activity for As(III) oxidation. The proposed oxidation process using charged TW membrane filters is practical and environmentally benign for the continuous treatment of As(III)-contaminated water during periods of unavailability of sunlight.

中文翻译:

预充电二氧化钛和三氧化钨复合催化剂膜过滤器中的原位产生的活性氧:在无辐射条件下应用于As(III)氧化。

这项研究表明,在预光充电的TiO 2和WO 3(TW)复合颗粒嵌入式无机膜滤池中原位产生的活性氧(ROSs)在没有任何辅助的情况下将亚砷酸盐(As(III))氧化为砷酸盐(As(V))。在黑暗条件下的化学氧化剂。TW膜过滤器已充满紫外线或模拟的阳光,随后转移到直流式流动系统中。带电的TW滤波器可以将存储的电子转移到溶解的O 2上,从而产生在黑暗中介导As(III)氧化的ROS。O 2显着抑制As(V)的产生去除或添加ROS淬灭剂表明ROS介导的As(III)氧化机理。电子顺磁光谱分析已确认在黑暗中形成了HO 2 / O 2 •–对。WO 3TW过滤器中的馏分会显着影响As(III)的氧化性能,而随着充电时间和溶液pH值的增加,As(V)的产量会增加。单充电的TW过滤器完全放电时,As(III)的氧化终止。但是,TW的充电恢复了As(III)氧化的催化活性。拟议的使用带电TW膜过滤器的氧化工艺在无日照期间连续处理被As(III)污染的水是实用且对环境无害的。
更新日期:2020-08-04
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