Zhang Xinzhe, Yang Zhihao, Bi Xiaoya, Zhang Yi, Liu Yage, Zhao Yanbao, Chen Jianping, Yu Laigui, Zou Xueyan
Engineering Research Center for Nanomaterials, The First Affiliated Hospital, The Academy for Advanced Interdisciplinary Studies, College of Chemistry and Molecular Sciences, Henan University Zhengzhou 450046 China
State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control, Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment of China Nanjing 210042 China.
RSC Adv. 2025 Aug 29;15(38):31005-31018. doi: 10.1039/d5ra02186c.
Nanoscale zero-valent iron (nZVI) was synthesized by a one-pot liquid-phase chemical method in the presence of FeSO as the iron source and NaBH as the reducing agent. The synthesized nZVI was characterized by scanning electron microscopy, X-ray diffraction, energy dispersive spectrometry, and Fourier transform infrared spectroscopy. Its ability to passivate Pb, Cd, and AsO in soils was evaluated by inductively coupled plasma-atomic emission spectroscopy, and the passivation mechanism was explored based on adsorption thermodynamics and kinetics simulations. It was found that nZVI is spherical in shape with a diameter of 60-80 nm and exhibited a satisfactory magnetic response, favoring facile recycling under a magnetic field, which could be directly applied to passivate Pb, Cd, and AsO in contaminated soils. The passivation ability for Pb, Cd, and AsO depended on the drying conditions and the dosage of NaBH. Notably, nZVI prepared with 4 g of NaBH under vacuum drying exhibited the strongest passivation ability. The adsorption of the tested heavy metals by nZVI conformed to the Langmuir isotherm model, and the correlation coefficients were 0.99 (Pb), 0.99 (Cd), and 0.93 (As), which indicated saturated monolayer adsorption. The corresponding maximum saturated adsorption amounts were 117.65 mg g (Pb), 45.45 mg g (Cd), and 6.82 mg g (As), respectively. Additionally, the adsorption by nZVI of the heavy metal ions under investigation followed the pseudo-second-order kinetic equation, referring to chemical adsorption, and the chemisorption percentages for Pb, Cd, and AsO were 93.0%, 74.8%, and 32.9%, respectively. This could account for the difference in the adsorption capacity of nZVI for the tested heavy metal ions. Moreover, 19 consecutive days of desorption experiments demonstrated that nZVI/M (M represents Pb, Cd, and As; , Pb, Cd, and AsO ) possessed strong stability. Our data indicate that nZVI has the potential to be an excellent nano-adsorbent with good passivation performance for the rapid and efficient passivation of Pb, Cd, and AsO in multi anion-cation co-contaminated soils.
采用一锅法液相化学法，以硫酸亚铁为铁源、硼氢化钠为还原剂合成了纳米零价铁（nZVI）。通过扫描电子显微镜、X射线衍射、能谱分析和傅里叶变换红外光谱对合成的nZVI进行了表征。采用电感耦合等离子体原子发射光谱法评估了其对土壤中铅、镉和砷酸根的钝化能力，并基于吸附热力学和动力学模拟探讨了钝化机制。结果表明，nZVI呈球形，直径为60 - 80 nm，具有良好的磁响应，有利于在磁场作用下轻松回收利用，可直接用于钝化污染土壤中的铅、镉和砷酸根。对铅、镉和砷酸根的钝化能力取决于干燥条件和硼氢化钠的用量。值得注意的是，在真空干燥条件下用4 g硼氢化钠制备的nZVI表现出最强的钝化能力。nZVI对所测试重金属的吸附符合朗缪尔等温线模型，相关系数分别为0.99（铅）、0.99（镉）和0.93（砷），表明为饱和单层吸附。相应的最大饱和吸附量分别为117.65 mg/g（铅）、45.45 mg/g（镉）和6.82 mg/g（砷）。此外，nZVI对所研究重金属离子的吸附遵循准二级动力学方程，属于化学吸附，铅、镉和砷酸根的化学吸附百分比分别为93.0%、74.8%和32.9%。这可以解释nZVI对所测试重金属离子吸附容量的差异。此外，连续19天的解吸实验表明，nZVI/M（M代表铅、镉和砷；即铅、镉和砷酸根）具有很强的稳定性。我们的数据表明，nZVI有潜力成为一种优异的纳米吸附剂，对多阴离子 - 阳离子共污染土壤中的铅、镉和砷酸根具有良好的钝化性能，能够快速有效地进行钝化。
