Comparison of two kinetic models of growth and reduction property of a strain of iron-reducing bacteria from an integrated NOx removal system

Environmental contextReactions in natural waters such as lakes and streams are thought to be extremely slow in the absence of sunlight (e.g. at night). We demonstrate that in the presence of iron, hydrogen peroxide and certain bacteria (all of which are common in natural waters), certain reactions may occur surprisingly quickly. These findings will help us predict the fate of many compounds, including pollutants, in natural waters at night. AbstractDark Fenton chemistry is an important source of hydroxyl radicals (OH•) in natural waters in the absence of sunlight. Hydroxyl radical production by this process is very slow in many bodies of water, owing to slow reduction and low solubility of FeIII at neutral and near-neutral pH. We have investigated the effects of the iron-reducing bacteria Shewanella oneidensis (SO) on OH• production rates from Fenton chemistry at environmentally relevant hydrogen peroxide (H2O2) and iron concentrations at neutral pH. In the presence of 2.0 × 10–4M H2O2, OH• production rates increased from 1.3 × 10–10 to 2.0 × 10–10Ms–1 in the presence of 7.0 × 106cellsmL–1 SO when iron (at a concentration of 100μM) was in the form of FeII, and from 3.6 × 10–11 to 2.2 × 10–10Ms–1 when iron was in the form of FeIII. This represents rate increases of factors of 1.5 and 6 respectively. We measured OH• production rates at a range of H2O2 concentrations and SO cell densities. Production rates depended linearly on both variables. We also demonstrate that bacteria-assisted Fenton chemistry can result in rapid degradation of aromatic pollutants such as anthracene. Our results suggest that iron-reducing bacteria such as SO may be important contributors to radical formation in dark natural waters.

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Alteration of iron-rich lacustrine sediments by dissimilatory iron-reducing bacteria

Geobiology ◽

10.1111/j.1472-4669.2006.00086.x ◽

2006 ◽

Vol 0 (0) ◽

pp. 061016061900003-??? ◽

Cited By ~ 3

Author(s):

S. A. CROWE ◽

J. A. ROBERTS ◽

C. G. WEISENER ◽

D. A. FOWLE

Keyword(s):

Lacustrine Sediments ◽

Iron Reducing Bacteria ◽

Reducing Bacteria

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Secondary mineral formation associated with respiration of nontronite, NAu-1 by iron reducing bacteria

Geochemical Transactions ◽

10.1063/1.2084787 ◽

2005 ◽

Vol 6 (4) ◽

pp. 67

Author(s):

S. Erin O’Reilly

Keyword(s):

Mineral Formation ◽

Secondary Mineral ◽

Iron Reducing Bacteria ◽

Secondary Mineral Formation ◽

Reducing Bacteria

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Can Primary Ferroan Dolomite and Ankerite Be Precipitated? Its Implications for Formation of Submarine Methane-Derived Authigenic Carbonate (MDAC) Chimney

Minerals ◽

10.3390/min9070413 ◽

2019 ◽

Vol 9 (7) ◽

pp. 413 ◽

Cited By ~ 2

Author(s):

Fan Xu ◽

Xuelian You ◽

Qing Li ◽

Yi Liu

Keyword(s):

Iron Reduction ◽

Extracellular Polymeric Substances ◽

Microbial Culture ◽

Reduction Zone ◽

Secondary Products ◽

Iron Reducing Bacteria ◽

Sulfate Reducing ◽

Dolomite Problem ◽

Reducing Bacteria ◽

Ferroan Dolomite

Microbes can mediate the precipitation of primary dolomite under surface conditions. Meanwhile, primary dolomite mediated by microbes often contains more Fe2+ than standard dolomite in modern microbial culture experiments. Ferroan dolomite and ankerite have been regarded as secondary products. This paper reviews the process and possible mechanisms of microbial mediated precipitation of primary ferroan dolomite and/or ankerite. In the microbial geochemical Fe cycle, many dissimilatory iron-reducing bacteria (DIRB), sulfate-reducing bacteria (SRB), and methanogens can reduce Fe3+ to Fe2+, while SRB and methanogens can also promote the precipitation of primary dolomite. There are an oxygen respiration zone (ORZ), an iron reduction zone (IRZ), a sulfate reduction zone (SRZ), and a methanogenesis zone (MZ) from top to bottom in the muddy sediment diagenesis zone. DIRB in IRZ provide the lower section with Fe2+, which composes many enzymes and proteins to participate in metabolic processes of SRB and methanogens. Lastly, heterogeneous nucleation of ferroan dolomite on extracellular polymeric substances (EPS) and cell surfaces is mediated by SRB and methanogens. Exploring the origin of microbial ferroan dolomite may help to solve the “dolomite problem”.

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