Insight into the degradation of Orange G by persulfate activated with biochar modified by iron and manganese oxides: Synergism between Fe and Mn
Insight into the degradation of Orange G by persulfate activated with biochar modified by iron and manganese oxides: Synergism between Fe and Mn
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DOI：
10.1016/j.jwpe.2020.101470
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发表时间：
2020-10-01
影响因子：
7
通讯作者：
Tao, Jiawei
中科院分区：
文献类型：
--
作者：
Hao, Huiru;Zhang, Qian;Tao, Jiawei
采用浸渍法制备了负载金属氧化物的污泥生物炭，包括单金属基污泥生物炭（Fe，F-SDBC; Mn，M-SDBC）和双金属基污泥生物炭（Fe，Mn，FM-SDBC）。结果表明，FM-SDBC比F/M-SDBC具有更高的活化能力。研究了不同pH条件下橙子G（OG）的降解情况。金属离子浸出和循环试验表明，FM-SDBC在过硫酸盐（PS）反复活化过程中具有非凡的稳定性和可重复使用性。猝灭研究表明，在FM-SDBC/PS体系中同时生成了SO 4中心点和OH中心点。反应前后Fe 2 p和Mn 2 p的XPS谱表明，PS对FM-SDBC的活化与Fe和Mn物种的氧化还原循环过程相伴随。动力学研究表明，在FM-SDBC/PS体系中，Mn在活化初期起主导作用，Fe在后续活化过程中起主导作用。FM-SDBC中Fe和Mn之间的协同作用机制可归因于：（1）Fe和Mn之间的相互电子转移;（2）Fe-Mn键的形成，在一定程度上促进了Fe和Mn之间的电子转移。基于上述协同机理，本研究制备的双金属基生物炭，尤其是FM-SDBC，具有高效、稳定、可重复使用和以废治废等优点，为硫酸根（SO 4中心点-）基高级氧化技术的实际应用提供了新的思路。
In this study, sludge-derived biochar (SDBC) loaded with metal oxides was successfully synthesized via a simple impregnation method, including monometallic-based SDBC (Fe, F-SDBC; Mn, M-SDBC) and bimetallic-based SDBC (Fe and Mn, FM-SDBC). Results demonstrated that FM-SDBC possessed higher activation capacity than F/M-SDBC. The degradation of Orange G (OG) under different pH were explored. Leaching of metal ions and cycling test showed that FM-SDBC possess extraordinary stability and reusability during repeated activation of persulfate (PS). It was evidenced by quenching studies that both SO4 center dot- and center dot OH center dot were generated in FM-SDBC/PS. The XPS spectra of Fe 2p and Mn 2p before and after reactions indicated that the activation of PS on FM-SDBC was in company with the redox cycling of Fe and Mn species. Through the kinetics study, the contribution of Mn occupied the dominant position at the beginning, and Fe did in subsequent activation process in FM-SDBC/PS system. Synergistic mechanism between Fe and Mn in FM-SDBC could be attributed to (1) mutual electron transfer between Fe and Mn; (2) the formation of Fe-Mn bonds, which facilitated electron transfer between Fe and Mn to some extent. Based on the synergistic mechanism aforementioned, bimetallic-based biochar, especially FM-SDBC prepared in this study, had the benefits of high efficiency, stability, reusability and waste control by waste, which provided new insights into sulfate radical (SO4 center dot-)-based advanced oxidation processes in practical application.