Long-term performance of enhanced biological phosphorus removal with increasing concentrations of silver nanoparticles and ions
Long-term performance of enhanced biological phosphorus removal with increasing concentrations of silver nanoparticles and ions
复制标题
随着银纳米颗粒和离子浓度的增加，增强生物除磷的长期性能
DOI：
10.1039/c3ra40989a
复制
发表时间：
2013-01-01
期刊：
影响因子：
3.9
通讯作者：
Mu, Hui
中科院分区：
文献类型：
--
作者：
Chen, Hong;Zheng, Xiong;Mu, Hui
银纳米粒子（AgNPs）和银离子（Ag+）作为抗菌剂的广泛应用引起了人们对其对环境（如污水处理厂）潜在影响的关注。本文报道了将进水AgNPs和Ag+从1 mg L−1增加到5 mg L−1对强化生物除磷（EBPR）性能的影响。无论在短期还是长期实验中，AgNPs的增加对EBPR均无显著影响。但随着Ag+浓度的突然增加，磷的去除率降低，长期培养后逐渐恢复。机制研究表明，当Ag+突然增加时，聚羟基烷酸酯和糖原的转化以及外多磷酸酶的活性下降，但长期培养后恢复。变性梯度凝胶电泳和荧光原位杂交分析表明，AgNPs和Ag+没有改变细菌群落结构和多磷酸盐积累生物的丰度。进一步的研究表明，长期暴露于Ag+增加了污泥胞外聚合物物质的数量，这可以减轻Ag+对EBPR关键酶和微生物的毒性。
The wide use of silver nanoparticles (AgNPs) and silver ions (Ag+) as antimicrobial agents have caused concerns about their potential effects on the environment, such as wastewater treatment plants. This paper reports the effects of increasing the influent AgNPs and Ag+ from 1 to 5 mg L−1 on the performance of enhanced biological phosphorus removal (EBPR). The increase of AgNPs showed no significant influence on EBPR in both short-term and long-term experiments. Phosphorus removal, however, was decreased by a sudden increase in Ag+ concentration and it was gradually recovered after long-term culture. The mechanism studies showed that the transformation of polyhydroxyalkanoates and glycogen and the activity of exopolyphosphatase declined when Ag+ was increased suddenly, but they were recovered after long-term culture. The denatured gradient gel electrophoresis and fluorescence in situ hybridization analyses indicated that the bacterial community structure and the abundance of polyphosphate accumulation organisms were not changed by AgNPs or Ag+. Further investigations revealed that the long-term exposure of Ag+ increased the amount of sludge extracellular polymeric substances, which accounted for the mitigation of Ag+ toxicity to the EBPR key enzyme and microbes.