| Autor: |
Grossman, Jarod N., Kahan, Tara F. |
| Předmět: |
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| Zdroj: |
Environmental Chemistry (14482517); 2016, Vol. 13 Issue 4, p757-766, 16p |
| Abstrakt: |
Dark 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 x 10-4 M H2O2, OH* production rates increased from 1.3 x 10-111110 to 2.0 x 10-1010 Ms-11 in the presence of 7.0 x 106 cells mL-1 SO when iron (at a concentration of 100 mM) was in the form of FeII, and from 3.6 x 10-11 to 2.2 x 10-10 M s-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. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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