Inhibition of sulfate reducing bacteria in aquifer sediment by iron nanoparticles

详细信息    查看全文

• 作者：Naresh Kumar ; Enoma O. Omoregie ; Jerome Rose ; Arm ; Masion ; Jonathan R. Lloyd ; Ludo Diels ; Leen Bastiaens
• 关键词：Zero valent iron ; Nano iron toxicity ; Sulfate reducing bacteria
• 刊名：Water Research
• 出版年：15 March, 2014
• 年：2014
• 卷：51
• 期：Complete
• 页码：64-72
• 全文大小：958 K

文摘

Batch microcosms were setup to determine the impact of different sized zero valent iron (Fe⁰) particles on microbial sulfate reduction during the in situ bio-precipitation of metals. The microcosms were constructed with aquifer sediment and groundwater from a low pH (3.1), heavy-metal contaminated aquifer. Nano (nFe⁰), micro (mFe⁰) and granular (gFe⁰) sized Fe⁰ particles were added to separate microcosms. Additionally, selected microcosms were also amended with glycerol as a C-source for sulfate-reducing bacteria. In addition to metal removal, Fe⁰ in microcosms also raised the pH from 3.1 to 6.5, and decreased the oxidation redox potential from initial values of 249 to 鈭?26聽mV, providing more favorable conditions for microbial sulfate reduction. mFe⁰ and gFe⁰ in combination with glycerol were found to enhance microbial sulfate reduction. However, no sulfate reduction occurred in the controls without Fe⁰ or in the microcosm amended with nFe⁰. A separate dose test confirmed the inhibition for sulfate reduction in presence of nFe⁰. Hydrogen produced by Fe⁰ was not capable of supporting microbial sulfate reduction as a lone electron donor in this study. Microbial analysis revealed that the addition of Fe⁰ and glycerol shifted the microbial community towards Desulfosporosinus sp. from a population initially dominated by low pH and metal-resisting Acidithiobacillus ferrooxidans.