College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China.
College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China.
J Colloid Interface Sci. 2021 Apr 15;588:776-786. doi: 10.1016/j.jcis.2020.11.111. Epub 2020 Dec 1.
In this work, the porosity, graphitization and iron doping of biochar were realized simultaneously by the pyrolysis of biomass and potassium ferrate (KFeO), then the iron-doped graphitized biochar was reduced to synthesize nanoscale zero-valent iron loaded porous graphitized biochar (nZVI/PGBC). 17β-estradiol (E2) is an environmental endocrine disruptor that can cause great harm to the environment in small doses. Experiments illustrated that nZVI/PGBC (100 mg/L) could completely remove E2 (3 mg/L) within 45 min by activating sodium persulfate (PS, 400 mg/L). The E2 removal efficiency of nZVI/PGBC was obviously superior to that of pristine biochar (BC), iron-doped graphitized biochar (Fe/GBC), nanoscale zero-valent iron (nZVI) and porous graphitized biochar (PGBC). The removal efficiency could be affected by reaction conditions, including reaction temperature, acidity, dosage of catalyst and oxidant and water matrix. Quenching experiments and electron spin resonance (ESR) demonstrated that SO and HO were both responsible for E2 degradation. This study indicated that Fe and Fe were the main catalytic active substances, while the catalytic ability of PGBC was not obvious. The reaction mechanism was proposed, that is, PS was activated by electrons provided by the redox reaction between Fe and Fe, and PGBC acted as the carrier of nZVI, the adsorbent of E2 and the mediator of electron-transfer. This study demonstrates that nZVI/PGBC can be used as an effective activator for PS to remove organic pollutants in water.
在这项工作中，通过生物质和高铁酸钾 (KFeO) 的热解同时实现了生物炭的多孔性、石墨化和铁掺杂，然后将铁掺杂的石墨化生物炭还原合成纳米零价铁负载多孔石墨化生物炭 (nZVI/PGBC)。17β-雌二醇 (E2) 是一种环境内分泌干扰物，即使在低剂量下也会对环境造成很大危害。实验表明，nZVI/PGBC（100mg/L）在 45min 内可通过激活过硫酸钠 (PS，400mg/L) 完全去除 3mg/L 的 E2。nZVI/PGBC 的 E2 去除效率明显优于原始生物炭 (BC)、铁掺杂石墨化生物炭 (Fe/GBC)、纳米零价铁 (nZVI) 和多孔石墨化生物炭 (PGBC)。去除效率会受到反应条件的影响，包括反应温度、酸度、催化剂和氧化剂的用量以及水基质。猝灭实验和电子自旋共振 (ESR) 表明 SO 和 HO 都对 E2 降解有贡献。本研究表明 Fe 和 Fe 是主要的催化活性物质，而 PGBC 的催化能力不明显。提出了反应机制，即 PS 被 Fe 和 Fe 之间的氧化还原反应提供的电子激活，PGBC 作为 nZVI 的载体、E2 的吸附剂和电子转移的介体。本研究表明，nZVI/PGBC 可作为 PS 去除水中有机污染物的有效活化剂。
