State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
Water Res. 2009 Dec;43(20):5243-51. doi: 10.1016/j.watres.2009.08.051. Epub 2009 Sep 8.
Nanoscale zero-valent iron (NZVI) particles were investigated in inactivating gram-positive Bacillus subtilis var. niger and gram-negative Pseudomonas fluorescens bacteria, and the fungus Aspergillus versicolor. NZVI particles were synthesized using NaBH(4) and Fe(NO(3))(3).9H(2)O, and the microbial suspensions were subjected to the treatments of NZVI particle suspensions with concentrations of 0.1, 1 and 10mg/ml for 5min. Field emission scanning electron microscope (FE-SEM) was used to characterize the synthesized NZVI particles, suspensions and the surface morphologies of the treated agents. FE-SEM images showed that the NZVI particles were spherical with a fairly uniform size of about 20-30nm, and the iron precipitates FeO(OH) appeared in needle-shape aggregates. When treated directly with NZVI particles under aerobic condition, the surfaces of microbes were quickly coated with needle-shape yellow-brown iron oxides. In this study, complete inactivation was achieved both for B. subtilis var. niger and P. fluorescens when treated with 10mg/ml NZVI particles with vigorous shaking under aerobic condition. When NZVI particle concentration decreased to 1, 0.1mg/ml, there was still a complete inactivation for P. fluorescens, while for B. subtilis var. niger the inactivation decreased to 95%, 80%, respectively. However, no inactivation was observed for the fungus A. versicolor when treated the same manner. Physical coating, disruption of membrane and generation of reactive oxygen species have played major roles in the inactivation observed.
纳米零价铁（NZVI）颗粒被用于研究其对革兰氏阳性枯草芽孢杆菌变种黑曲霉和革兰氏阴性荧光假单胞菌以及真菌曲霉的灭活作用。NZVI 颗粒是使用 NaBH4 和 Fe(NO3)3·9H2O 合成的，将微生物悬浮液与浓度为 0.1、1 和 10mg/ml 的 NZVI 颗粒悬浮液分别处理 5min。场发射扫描电子显微镜（FE-SEM）用于对合成的 NZVI 颗粒、悬浮液以及处理剂的表面形态进行特征化分析。FE-SEM 图像显示，NZVI 颗粒呈球形，大小相当均匀，约为 20-30nm，铁沉淀物 FeO(OH)以针状聚集体的形式出现。当在有氧条件下直接用 NZVI 颗粒处理时，微生物的表面很快被针状黄棕色氧化铁覆盖。在这项研究中，当在有氧条件下剧烈搅拌时，用 10mg/ml 的 NZVI 颗粒处理可实现枯草芽孢杆菌变种黑曲霉和荧光假单胞菌的完全灭活。当 NZVI 颗粒浓度降低至 1mg/ml 和 0.1mg/ml 时，对于荧光假单胞菌仍然可以实现完全灭活，而对于枯草芽孢杆菌变种黑曲霉，灭活率分别降低至 95%和 80%。然而，以同样的方式处理真菌曲霉时，并没有观察到灭活现象。物理覆盖、膜破坏和活性氧的生成在观察到的灭活中起主要作用。
