Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
Environ Pollut. 2020 Jun;261:114020. doi: 10.1016/j.envpol.2020.114020. Epub 2020 Jan 21.
Nano-magnetite supported by biochar (nFeO/BC) pyrolyzed at temperatures of 300 °C-600 °C was developed to activate hydrogen peroxide (HO) for the efficient degradation of ethylbenzene in aqueous solution. It was revealed that the degradation efficiency of ethylbenzene and TOC removal were 96.9% and 36.2% respectively after the reaction for 40 min in the presence of initial concentration of 0.1 mmol L ethylbenzene, 2.76 g L nFeO/BC with the mass ratio of nFeO to BC of 4:1 and 2.0 mmol L HO at pH 7.0. Based on electron paramagnetic resonance (EPR), quenching experiment and X-ray photoelectron spectroscopy (XPS) data, both OH and O radicals were generated in the nFeO/BC activated HO system, and the OH radicals were the predominant species for the degradation of ethylbenzene. Through electron transfer process, mechanisms of Fe(II), phenolic hydroxyl group and persistent free radicals (PFRs) on BC surfaces accounted for the generation of OH radicals, and Fe(III) in nFeO and formed from Fe(II) oxidation responsible for the generation of O radicals in the nFeO/BC activated HO system were proposed.
采用生物炭负载纳米磁铁矿（nFeO/BC），在 300-600°C 下进行热解，制备了用于活化过氧化物（HO）以有效降解水溶液中乙苯的纳米复合材料。结果表明，在初始浓度为 0.1mmol/L 乙苯、质量比为 4:1 的 nFeO/BC（nFeO 与 BC 的质量比为 4:1）和 2.0mmol/L HO、pH 值为 7.0 的条件下，反应 40min 后，乙苯的降解效率和总有机碳（TOC）去除率分别达到 96.9%和 36.2%。基于电子顺磁共振（EPR）、猝灭实验和 X 射线光电子能谱（XPS）数据分析，在 nFeO/BC 活化过氧化物体系中生成了·OH 和·O 自由基，其中·OH 是降解乙苯的主要活性物种。通过电子传递过程，提出了 BC 表面的 Fe(II)、酚羟基和持久自由基（PFRs）以及 nFeO 中由 Fe(II)氧化形成的 Fe(III)生成·OH 自由基的机制，用于解释 nFeO/BC 活化过氧化物体系中生成·O 自由基的原因。
