标题: Electron transfer-based peroxydisulfate activation by waste herb residue biochar: Adsorption versus surface oxidation

作者: Chen, XT (Chen, Xuantong); Guo, Z (Guo, Zhen); Liu, JM (Liu, Juemiao); Wu, F (Wu, Fei); Cheng, C (Cheng, Cheng); Lin, H (Lin, Heng); Ren, W (Ren, Wei); Zhang, H (Zhang, Hui)

来源出版物: CHEMICAL ENGINEERING JOURNAL 卷: 451 文献号: 138560 DOI: 10.1016/j.cej.2022.138560 子辑: 1 出版年: JAN 1 2023

摘要: Waste herb residue biochar (WBC) was synthesized to activate peroxydisulfate (PDS) for the removal of different micropollutants. WBC prepared at 700 C (WBC700) exhibits discrepant adsorption and PDS catalytic perfor-mance to three pharmaceuticals and four phenolic compounds. At 60 min reaction time, the adsorptive removal by 0.5 g/L WBC700 varied from 31.3% (clofibric acid) to 97.6% (4-chlorophenol), while the apparent removal ranged from 36.1% (clofibric acid) to 99.5% (4-chlorophenol) when 0.5 g/L WBC700 and 1.0 mM PDS were applied. The oxidation of the micropollutants involves electron transfer mechanism via the surface-confined metastable reactive complexes (WBC-PDS*), which was verified by electrochemical tests, quenching experiments, electron paramagnetic resonance, Fourier transform infrared and in-situ Raman spectroscopy. The observed pseudo first-order kinetic constant (k(obs)) of organic removal did not exhibit a good correlation with its electrochemical redox descriptor (half-wave potential, phi(1/2), for example) as reported in the previous studies. Instead, the surface oxidation rate constant (k(oxid)), determined from a dynamic model considering liquid-solid mass transfer of micropollutant and the sequent surface oxidation by WBC-PDS* complexes, was highly related to phi(1/2). In parallel, the liquid-solid mass transfer coefficient (K(L)a) of micropollutant was obtained from a similar model excluding the surface oxidation, and k(obs) showed a more significant association with K(L)a than with adsorption capacity (Q(e)). This study provides a promising approach to understand the role of adsorption and surface oxidation in an electron transfer-dominated persulfate activation process.

作者关键词: Adsorption; Biochar; Electron transfer; Mass transfer; Peroxydisulfate; Surface oxidation

地址: [Chen, Xuantong; Guo, Zhen; Liu, Juemiao; Wu, Fei; Cheng, Cheng; Lin, Heng; Zhang, Hui] Wuhan Univ, Sch Resource & Environm Sci, Dept Environm Sci & Engn, Hubei Key Lab Biomass Resource Chem & Environm Bio, Wuhan 430079, Peoples R China.

[Lin, Heng] Wuhan Univ, Dept Cardiothorac Surg, ZhongNan Hosp, Wuhan 430060, Peoples R China.

[Ren, Wei] Nanchang Hangkong Univ, Key Lab Jiangxi Prov Persistent Pollutants Control, Nanchang 330063, Peoples R China.

通讯作者地址: Lin, H; Zhang, H (通讯作者)，Wuhan Univ, Sch Resource & Environm Sci, Dept Environm Sci & Engn, Hubei Key Lab Biomass Resource Chem & Environm Bio, Wuhan 430079, Peoples R China.

Lin, H (通讯作者)，Wuhan Univ, Dept Cardiothorac Surg, ZhongNan Hosp, Wuhan 430060, Peoples R China.

Ren, W (通讯作者)，Nanchang Hangkong Univ, Key Lab Jiangxi Prov Persistent Pollutants Control, Nanchang 330063, Peoples R China.

电子邮件地址: lheng2005@163.com; renwei9528@163.com; eeng@whu.edu.cn

影响因子：16.744