Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing, Jiangsu, 210096, China.
School of Mechanical Engineering, Southeast University, Nanjing, Jiangsu, 210096, China.
J Environ Manage. 2024 Aug;366:121805. doi: 10.1016/j.jenvman.2024.121805. Epub 2024 Jul 16.
Sulfurized nanoscale zero-valent iron supported on biochar (BC-SNZVI) has been successfully synthesized for 2,4,6-trichlorophenol (2,4,6-TCP) removal, while was only effectively under acidic conditions. To obtain highly efficient removal of 2,4,6-TCP within a broader pH range, weak static magnetic fields (WMF) was applied in BC-SNZVI/2,4,6-TCP aqueous systems. Results showed 30 mT WMF supported the most extensive 2,4,6-TCP removal, and 87.4% of 2,4,6-TCP (initial concentration of 30 mg/L) was removed by 0.5 g/L BC-SNZVI at neutral pH (pH = 6.8) within 180 min, which was increased by 54.4% compared to that without WMF. The observed rate constant (K) under 30 mT WMF was 2.1-fold greater than that without WMF. Although three typical anions (NO (0.5-10.0 mM), HPO (0.05-0.5 mM), and HCO (0.5-5.0 mM)) still inhibited 2,4,6-TCP removal, WMF could efficiently alleviate the inhibitory effects. Moreover, 73.1% of 2,4,6-TCP was successfully removed by BC-SNZVI under WMF in natural water. WMF remarkably boosted the dechlorination of 2,4,6-TCP, increasing the 2,4,6-TCP dechlorination efficiency from 45.2% (in the absence of WMF) to 83.8% (in the presence of WMF) by the end of 300 min. And the complete dechlorination product phenol appeared within 10 min. Force analysis confirmed the magnetic field gradient force (F) moved paramagnetic Fe at the SNZVI surface along the direction perpendicular to the external applied field, promoting the mass-transfer controlled SNZVI corrosion. Corrosion resistance analysis revealed WMF promoted the electron-transfer controlled SNZVI corrosion by decreasing its self-corrosion potential (E). With the introduction of sulfur, the magnitude of F doubled and the E decreased comparing with NZVI. Our findings provide a facile and viable strategy for treating chlorinated phenols at neutral pH.
负载在生物炭上的硫化纳米零价铁（BC-SNZVI）已成功合成用于 2,4,6-三氯苯酚（2,4,6-TCP）的去除，但仅在酸性条件下有效。为了在更宽的 pH 范围内获得高效去除 2,4,6-TCP 的效果，在 BC-SNZVI/2,4,6-TCP 水体系中引入了弱静磁场（WMF）。结果表明，30 mT 的 WMF 支持最广泛的 2,4,6-TCP 去除，在中性 pH（pH = 6.8）下，0.5 g/L 的 BC-SNZVI 在 180 min 内去除了 87.4%的初始浓度为 30 mg/L 的 2,4,6-TCP，与无 WMF 相比增加了 54.4%。在 30 mT 的 WMF 下观察到的反应速率常数（K）是无 WMF 下的 2.1 倍。尽管三种典型的阴离子（NO（0.5-10.0 mM）、HPO（0.05-0.5 mM）和 HCO（0.5-5.0 mM））仍然抑制了 2,4,6-TCP 的去除，但 WMF 可以有效地缓解其抑制作用。此外，在天然水中，BC-SNZVI 在 WMF 作用下可有效去除 73.1%的 2,4,6-TCP。WMF 显著促进了 2,4,6-TCP 的脱氯，在 300 min 结束时，2,4,6-TCP 的脱氯效率从无 WMF 时的 45.2%增加到有 WMF 时的 83.8%。并且完全脱氯产物苯酚在 10 min 内出现。力分析证实，磁场梯度力（F）沿垂直于外加磁场的方向将顺磁 Fe 移动到 SNZVI 表面，从而促进了质量传递控制的 SNZVI 腐蚀。耐腐蚀性分析表明，WMF 通过降低其自腐蚀电位（E）促进了电子传递控制的 SNZVI 腐蚀。引入硫后，F 的大小增加了一倍，与 NZVI 相比，E 降低了。我们的研究结果为在中性 pH 下处理氯化酚类化合物提供了一种简便可行的策略。
