Impact of nano zero valent iron (NZVI) on methanogenic activity and population dynamics in anaerobic digestion
Impact of nano zero valent iron (NZVI) on methanogenic activity and population dynamics in anaerobic digestion
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DOI：
10.1016/j.watres.2013.09.012
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发表时间：
2013-11-01
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：
Yang, Yu;Guo, Jialiang;Hu, Zhiqiang
纳米零价铁（NZVI）虽然越来越多地用于环境修复，但对厌氧消化中的产甲烷作用具有潜在的负面影响。在这项研究中，NZVI（平均大小 = 55 +/- 11 nm）由于破坏细胞完整性而显示出对产甲烷的抑制。这种抑制与厌氧条件下 NZVI 溶解导致的快速氢气产生和积累同时发生。当浓度为 1 mM 及以上时，NZVI 可使甲烷产量减少 20% 以上。在浓度为 30 mM 时，NZVI 导致混合液中可溶性 COD（细胞破裂的指标）和挥发性脂肪酸显着增加，同时 H-2 积累，导致甲烷产量减少 69%（+/- 4% [标准偏差]）。通过在含有30 mM NZVI的厌氧污泥中添加特定的产甲烷抑制剂——2-溴乙磺酸钠（BES），产生的H-2量仅为热灭活污泥的79%（+/- 1%），表明细菌控制的氢利用过程发生。定量PCR数据与产甲烷抑制的结果一致，因为在30 mM NZVI存在下，产甲烷群体（以Methanosaeta为主）的水平与对照相比显着下降。相反，ZVI粉末（平均尺寸
Nano zero valent iron (NZVI), although being increasingly used for environmental remediation, has potential negative impact on methanogenesis in anaerobic digestion. In this study, NZVI (average size = 55 +/- 11 nm) showed inhibition of methanogenesis due to its disruption of cell integrity. The inhibition was coincident with the fast hydrogen production and accumulation due to NZVI dissolution under anaerobic conditions. At the concentrations of 1 mM and above, NZVI reduced methane production by more than 20%. At the concentration of 30 mM, NZVI led to a significant increase in soluble COD (an indication of cell disruption) and volatile fatty acids in the mixed liquor along with an accumulation of H-2, resulting in a reduction of methane production by 69% (+/- 4% [standard deviation]). By adding a specific methanogenesis inhibitor-sodium 2-bromoethanesulfonate (BES) to the anaerobic sludge containing 30 mM NZVI, the amount of H-2 produced was only 79% (+/- 1%) of that with heat-killed sludge, indicating the occurrence of bacterially controlled hydrogen utilization processes. Quantitative PCR data was in accordance with the result of methanogenesis inhibition, as the level of methanogenic population (dominated by Methanosaeta) in the presence of 30 mM NZVI decreased significantly compared to that of the control. On the contrary, ZVI powder (average size