Alumina nanoparticles-induced effects on wastewater nitrogen and phosphorus removal after short-term and long-term exposure
Alumina nanoparticles-induced effects on wastewater nitrogen and phosphorus removal after short-term and long-term exposure
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DOI：
10.1016/j.watres.2012.05.042
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发表时间：
2012-09-15
期刊：
影响因子：
12.8
通讯作者：
Yang, Hong
中科院分区：
文献类型：
--
作者：
Chen, Yinguang;Su, Yinglong;Yang, Hong
氧化铝纳米颗粒（Al2O3 NPs）广泛应用于许多领域，其潜在的健康和环境风险日益引起人们的关注。然而，它们对废水脱氮除磷的可能影响尚未见报道。在本研究中，研究了Al2O3 NPs对废水中营养物去除的短期和长期影响。扫描电镜（SEM）分析表明，大部分Al2O3 NPs被吸附在活性污泥上，但这些NPs对活性污泥的表面完整性和活力没有不利影响。研究发现，短期暴露于1和50 mg/L的Al2O3 NPs对废水的硝化、反硝化和除磷影响较小。然而，长期暴露于50 mg/L Al2O3 NPs中，由于抑制了反硝化过程，观察到总氮（TN）去除率从80.4%降低到62.5%，尽管生物除磷和细胞内聚羟基烷酸酯和糖原的转化不受影响。定量PCR分析表明，与对照组相比，50 mg/L Al2O3 NPs降低了活性污泥中反硝化细菌的丰度。进一步的酶活性测试表明，关键反硝化酶（硝酸盐还原酶和亚硝酸盐还原酶）的活性受到抑制，这可能是长期暴露于50 mg/L Al2O3 NPs后对废水脱氮产生负面影响的原因。(C) 2012 Elsevier Ltd.版权所有。
Alumina nanoparticles (Al2O3 NPs) have been widely used in many fields, which causes a growing concern about their potential health and environmental risks. However, their possible impacts on wastewater nitrogen and phosphorus removal have not yet been reported. In this study, both short-term and long-term effects of Al2O3 NPs on wastewater nutrient removal were investigated. Scanning electron microscope (SEM) analysis showed that most of Al2O3 NPs were adsorbed onto activated sludge, but these NPs had no adverse effects on the surface integrity and viability of activated sludge. It was found that short-term exposure to 1 and 50 mg/L Al2O3 NPs induced marginal influences on wastewater nitrification, denitrification and phosphorus removal. Nevertheless, the prolonged exposure to 50 mg/L Al2O3 NPs was observed to decrease the total nitrogen (TN) removal efficiency from 80.4% to 62.5% due to the suppressed denitrification process, although biological phosphorus removal and the transformations of intracellular poly-hydroxyalkanoates and glycogen were not affected. Quantitative PCR assays indicated that compared with the control, 50 mg/L Al2O3 NPs decreased the abundance of denitrifying bacteria in activated sludge. Further enzyme activity tests showed that the activities of key denitrifying enzymes (nitrate reductase and nitrite reductase) were inhibited, which might be responsible for the negative effects of 50 mg/L Al2O3 NPs on wastewater nitrogen removal after long-term exposure. (C) 2012 Elsevier Ltd. All rights reserved.