Role of sulfide and ligand strength in controlling nanosilver toxicity
Role of sulfide and ligand strength in controlling nanosilver toxicity
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DOI：
10.1016/j.watres.2009.01.029
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发表时间：
2009-04-01
期刊：
影响因子：
12.8
通讯作者：
Hu, Zhiqiang
中科院分区：
文献类型：
--
作者：
Choi, Okkyoung;Cleuenger, Thomas E.;Hu, Zhiqiang
纳米银因其强大的抗菌特性而被广泛应用于纳米技术增强的消费品中。这些产品释放的银纳米颗粒 (AgNP) 可能会进入废水收集和处理系统。这项研究评估了硫化物和配体强度在控制纳米银对废水处理中重要的硝化细菌的毒性方面的作用。在废水中常见的配体（SO42-、S2-、Cl-、PO43- 和 EDTA(-)）不存在和存在的情况下，纳米银的毒性通过吸氧率测量来确定。硫化物似乎是有效降低纳米银毒性的唯一配体。通过添加一小部分与 AgNP 化学计量复合的硫化物，纳米银对硝化生物的毒性最多可降低 80%。扫描电子显微镜结合能量色散 X 射线分析表明，AgNPs 与硫化物高度反应，形成新的 AgxSy 络合物或沉淀物。这些复合物在长时间曝气（18小时）后没有被氧化。该信息对于废水处理设计和操作非常有用，可通过硫化物络合减少纳米银的毒性。虽然生物配体模型成功预测了Ag+离子的毒性，但无法准确预测AgNPs的毒性。尽管如此，它可能是可用于预测和控制纳米银对废水微生物的毒性的众多工具之一。 (C) 2009 Elsevier Ltd. 保留所有权利。
Nanosilver has been used broadly in nanotechnology enhanced consumer products because of its strong antimicrobial properties. Silver nanoparticles (AgNPs) released from these products will likely enter wastewater collection and treatment systems. This research evaluated the role of sulfide and ligand strength in controlling nanosilver toxicity to nitrifying bacteria that are important in wastewater treatment. The nanosilver toxicity in the absence and presence of ligands (SO42-, S2-, Cl-, PO43-, and EDTA(-)) commonly present in wastewater was determined from the oxygen uptake rate measurements. Sulfide appeared to be the only ligand to effectively reduce nanosilver toxicity. By adding a small aliquot of sulfide that was stoichiometrically complexed with AgNPs, the nanosilver toxicity to nitrifying organisms was reduced by up to 80%. Scanning electron microscopy coupled with energy dispersive X-ray analysis indicated that AgNPs were highly reactive with sulfide to form new AgxSy complexes or precipitates. These complexes were not oxidized after a prolonged period of aeration (18 h). This information is useful for wastewater treatment design and operation to reduce nanosilver toxicity via sulfide complexation. While the biotic ligand model was successful in predicting the toxicity of Ag+ ions, it could not accurately predict the toxicity of AgNPs. Nevertheless, it could be one of the many tools useful in predicting and controlling nanosilver toxicity to wastewater microorganisms. (C) 2009 Elsevier Ltd. All rights reserved.