State Key Laboratory of Chemical Engineering, Tianjin Key Laboratory of Membrane Science and Desalination Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China.
Zhejiang Institute of Tianjin University, Ningbo, Zhejiang 315201, PR China; Tianjin Key Laboratory for Marine Environmental Research and Service, School of Marine Science and Technology, Tianjin University, Tianjin 300072, PR China.
Water Res. 2023 Sep 1;243:120420. doi: 10.1016/j.watres.2023.120420. Epub 2023 Jul 27.
Chloroform (CF) is a recalcitrant halogenated methane (HM) that has received widespread attention due to its frequent detection in groundwater and its potential carcinogenic risk. In this study, TEMPO-oxidized cellulose nanofiber-supported iron/copper bimetallic nanoparticles (TOCNF-Fe/Cu), a novel composite catalyst, was synthesized to activate sodium percarbonate (SPC) for the removal of CF from groundwater. The results showed that over 96.3% of CF could be removed in a neutral reaction medium (pH 6.5-9) within 180 min using 0.66 g L of TOCNF (0.32)-Fe/Cu (1) and 1 mM of SPC, which outperforms typical advanced oxidation processes. The reaction mechanism of the TOCNF-Fe/Cu-SPC system for the CF removal was elucidated. As demonstrated through electron paramagnetic resonance and quenching experiments, the TOCNF-Fe/Cu-SPC system was found to include OH and O, where the latter played a dominant role in the CF removal. DFT calculations indicated that TOCNF improved the electron transport capability of Fe/Cu and reduced the transition state energy. The Fe species on the surface of TOCNF-Fe/Cu were identified as the primary active sites for SPC activation, whereas the Cu species were beneficial to the regeneration of the Fe species. Additionally, TOCNF-Fe/Cu was found to have good recyclability and stability. The feasibility of the TOCNF-Fe/Cu-SPC system was further confirmed by applying it for the efficient removal of composite HMs from actually contaminated groundwater. Overall, the TOCNF-Fe/Cu-SPC system is an attractive candidate for the treatment of HM-contaminated groundwater.
三氯甲烷（CF）是一种难降解的卤代甲烷（HM），由于其在地下水环境中的频繁检出及其潜在的致癌风险，而受到广泛关注。在本研究中，我们制备了一种新型复合催化剂——TEMPO 氧化纤维素纳米纤维负载铁/铜双金属纳米粒子（TOCNF-Fe/Cu），用于激活过碳酸钠（SPC）去除地下水中的 CF。结果表明，在中性反应介质（pH 6.5-9）中，使用 0.66 g/L 的 TOCNF（0.32）-Fe/Cu（1）和 1 mM 的 SPC，可在 180 min 内去除超过 96.3%的 CF，其性能优于典型的高级氧化工艺。阐明了 TOCNF-Fe/Cu-SPC 体系去除 CF 的反应机制。通过电子顺磁共振和猝灭实验证明，该体系中包含 OH 和 O，其中后者在 CF 的去除中起主要作用。DFT 计算表明，TOCNF 提高了 Fe/Cu 的电子传输能力并降低了过渡态能量。TOCNF-Fe/Cu 表面的 Fe 物种被认为是 SPC 活化的主要活性位，而 Cu 物种有利于 Fe 物种的再生。此外，TOCNF-Fe/Cu 还具有良好的可回收性和稳定性。通过将 TOCNF-Fe/Cu-SPC 体系应用于实际受污染地下水的复合 HM 高效去除，进一步验证了其可行性。总之，TOCNF-Fe/Cu-SPC 体系是一种有吸引力的处理 HM 污染地下水的候选方案。
