Fate of Zinc Oxide Nanoparticles during Anaerobic Digestion of Wastewater and Post-Treatment Processing of Sewage Sludge
Fate of Zinc Oxide Nanoparticles during Anaerobic Digestion of Wastewater and Post-Treatment Processing of Sewage Sludge
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DOI：
10.1021/es301487s
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发表时间：
2012-08-21
影响因子：
11.4
通讯作者：
Scheckel, Kirk G.
中科院分区：
文献类型：
--
作者：
Lombi, Enzo;Donner, Erica;Scheckel, Kirk G.
纳米材料的快速发展和商业化将不可避免地导致纳米颗粒（NPs）释放到环境中。由于纳米颗粒通常表现出与其分子或大尺寸类似物显著不同的物理和化学性质，因此人们越来越关注它们在环境分区中的命运和毒性。废水污泥途径已被确定为导致环境暴露于NPs的关键释放途径。在这项研究中，我们研究了两种ZnO-NP和一种疏水性ZnO-NP商业制剂（用于个人护理产品）在废水厌氧消化过程中的化学转化。锌形态的变化作为后处理的污水污泥，模仿堆肥/堆放的结果，也进行了评估。结果表明，“天然”锌和以可溶性盐或NP形式添加的锌在所有处理中均迅速转化为硫化物。商业制剂的疏水性阻碍了ZnO-NP的转化。然而，在结束的厌氧消化过程和后处理的污水污泥（这引起了显着的变化，锌形态），形态的锌是相似的所有治疗。这表明，至少对于测试的材料，通过这种暴露途径的氧化锌-NP的风险评估可以依赖于已经获得的关于污水污泥中存在的其他“常规”形式的锌的重要知识。
The rapid development and commercialization of nanomaterials will inevitably result in the release of nanoparticles (NPs) to the environment. As NPs often exhibit physical and chemical properties significantly different from those of their molecular or macrosize analogs, concern has been growing regarding their fate and toxicity in environmental compartments. The wastewater sewage sludge pathway has been identified as a key release pathway leading to environmental exposure to NPs. In this study, we investigated the chemical transformation of two ZnO-NPs and one hydrophobic ZnO-NP commercial formulation (used in personal care products), during anaerobic digestion of wastewater. Changes in Zn speciation as a result of postprocessing of the sewage sludge, mimicking composting/stockpiling, were also assessed. The results indicated that "native" Zn and Zn added either as a soluble salt or as NPs was rapidly converted to sulfides in all treatments. The hydrophobicity of the commercial formulation retarded the conversion of ZnO-NP. However, at the end of the anaerobic digestion process and after postprocessing of the sewage sludge (which caused a significant change in Zn speciation), the speciation of Zn was similar across all treatments. This indicates that, at least for the material tested, the risk assessment of ZnO-NP through this exposure pathway can rely on the significant knowledge already available in regard to other "conventional" forms of Zn present in sewage sludge.