Efficient degradation of tetrabromobisphenol A via electrochemical sequential reduction-oxidation: Degradation efficiency, intermediates, and pathway.
Efficient degradation of tetrabromobisphenol A via electrochemical sequential reduction-oxidation: Degradation efficiency, intermediates, and pathway.
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DOI：
10.1016/j.jhazmat.2017.10.004
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发表时间：
2018-02
影响因子：
13.6
通讯作者：
Yanping Hou;Zhen Peng;Li Wang;Zebin Yu;Lirong Huang;Lingfang Sun;Jun Huang
中科院分区：
文献类型：
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作者：
Yanping Hou;Zhen Peng;Li Wang;Zebin Yu;Lirong Huang;Lingfang Sun;Jun Huang
四溴双酚A（TBBPA）是一种有毒的持久性污染物，必须从环境中有效去除。本研究以Pd-Fe纳米粒子修饰的泡沫镍（Pd-Fe/Ni）电极为阴极，通过控制反应气氛，建立了电化学顺序还原氧化体系降解四溴双酚A（TBBPA）。为了获得一种有效的Pd-Fe/Ni电极用于TBBPA的降解，各种因素，如Pd负载量，Fe 2+添加量进行了研究。Pd-Fe/Ni电极具有较高的TBBPA转化率和脱溴率，这是由于Fe 0和电化学还原的协同作用。结果表明，单独通入N2和通入N2后通入空气两种情况下，TBBPA的转化率和脱溴率基本相同，均高于通入空气的情况。首先通入N2发生还原脱溴反应，生成tri-BBPA、di-BBPA、mono-BBPA和BPA，这些中间产物很可能被H2 O2与Pd-Fe/Ni电极在曝气条件下生成的dotOH自由基进一步氧化。通过HPLC和UPLC-QTOF-MS鉴定了TBBPA降解过程中的还原和氧化中间体（包括芳香开环产物），并根据中间体的性质提出了TBBPA降解的可能机理和途径。研究表明，N2+空气鼓泡调控的序贯还原-氧化过程有利于TBBPA的降解，是一种很有前途的HOCs降解过程。
Tetrabromobisphenol A (TBBPA), a toxic persistent pollutant, should be effectively removed from the environment. In this study, an electrochemical sequential reduction-oxidation system was proposed by controlling reaction atmosphere with Pd-Fe nanoparticles modified Ni foam (Pd-Fe/Ni) electrode as cathode for TBBPA degradation. To obtain an efficient Pd-Fe/Ni electrode for TBBPA degradation, various factors, like Pd loading, Fe2+adding amounts, were examined. The Pd-Fe/Ni electrode exhibited higher TBBPA conversion and debromination than the counterparts, due to the synergism of Fe0and electrochemical reduction. Similar TBBPA conversions and debromination ratios were observed for the cases of sparging N2only and sparging N2followed by air, which were higher than those of aeration. Reductive debromination occurred while first bubbling N2, forming tri-BBPA, di-BBPA, mono-BBPA and BPA; and these intermediates were likely to be further oxidized by radical dotOH generated from H2O2together with Pd-Fe/Ni electrode under aeration. Reductive and oxidative intermediates (including aromatic ring-opened product) were identified by HPLC and UPLC-QTOF-MS. Based on the intermediates, the possible TBBPA degradation mechanism and pathway were proposed. This study demonstrates that sequential reduction-oxidation process tuned by N2and air bubbling was favored for TBBPA degradation, thus, it should be a promising process for HOCs degradation.