College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing, Zhejiang, 312000, China.
College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing, Zhejiang, 312000, China.
Environ Pollut. 2023 Oct 1;334:122208. doi: 10.1016/j.envpol.2023.122208. Epub 2023 Jul 14.
Co-activation of HO with biochar and iron sources together provides an attractive strategy for efficient removal of refractory pollutants, because it can solve the problems of slow Fe(Ⅱ) regeneration in Fenton/Fenton-like processes and of low OH yield in biochar-activated process. In this study, a wood-derived biochar (WB) was modified by heteroatom doping for the objective of enhancing its reactivity toward co-activation of HO. The performance of the co-activated system using doped biochars and trace dissolved Fe(Ⅲ) on oxidation of organic pollutants was evaluated for the first time. The characterizations using X-ray photoelectron spectroscopy (XPS), Raman spectra and electrochemical analyses indicate that heteroatom doping introduced more defects in biochar and improved its electron transfer capacity. The oxidation experiments show that heteroatom doping improved the performance of biochar in the co-activated process, in which the N,S-codoped biochar (NSB) outperformed the N-doped biochar (NB) on oxidation of pollutants. The reaction rate constant (k) for oxidation of sulfadiazine in NSB + Fe + HO is 2.25 times that in NB + Fe + HO, and is 72.9 times that in the Fenton-like process without biochar, respectively. The mechanism investigations indicate that heteroatom doping enhanced biochar's reactivity on catalyzing the decomposition of HO and on reduction of Fe(Ⅲ) due to the improved electron transfer/donation capacity. In comparison with N-doping, N,S-codoping provided additional electron donor (thiophenic C-S-C) for faster regeneration of Fe(Ⅱ) with less amount of doping reagent used. Furthermore, co-activation with NSB maintained to be efficient at a milder acidic pH than Fenton/Fenton-like processes, and can be used for oxidation of different pollutants and in real water. Therefore, this research provides a novel, sustainable and cost-efficient method for oxidation of refractory pollutants.
HO 与生物炭和铁源的共激活为有效去除难处理污染物提供了一种有吸引力的策略，因为它可以解决 Fenton/Fenton 类过程中 Fe(II)再生缓慢和生物炭激活过程中 OH 产量低的问题。在这项研究中，通过杂原子掺杂改性了一种木质衍生生物炭（WB），旨在增强其对 HO 共激活的反应性。首次评估了掺杂生物炭和痕量溶解 Fe(III)在氧化有机污染物方面的共激活体系的性能。X 射线光电子能谱（XPS）、拉曼光谱和电化学分析的特性表明，杂原子掺杂在生物炭中引入了更多的缺陷并提高了其电子转移能力。氧化实验表明，杂原子掺杂改善了生物炭在共激活过程中的性能，其中 N，S 共掺杂生物炭（NSB）在氧化污染物方面优于 N 掺杂生物炭（NB）。在 NSB+Fe+HO 中氧化磺胺嘧啶的反应速率常数（k）是 NB+Fe+HO 的 2.25 倍，分别是没有生物炭的类 Fenton 过程的 72.9 倍。机理研究表明，由于电子转移/供体能力的提高，杂原子掺杂增强了生物炭在催化 HO 分解和还原 Fe(III)方面的反应性。与 N 掺杂相比，N，S 共掺杂为更快地再生 Fe(II)提供了额外的电子供体（噻吩 C-S-C），且使用的掺杂试剂更少。此外，与 Fenton/Fenton 类工艺相比，NSB 的共激活在较温和的酸性 pH 下仍保持高效，并可用于氧化不同的污染物和实际水样。因此，这项研究为氧化难处理污染物提供了一种新颖、可持续和具有成本效益的方法。
