Volatilization of mercury under acidic conditions from mercury-polluted soil by a mercury-resistant Acidithiobacillus ferrooxidans SUG 2-2.
Volatilization of mercury under acidic conditions from soil polluted with mercuric chloride (1.5 mg Hg/kg soil) was studied with resting cells of a mercury-resistant strain, Acidithiobacillus ferrooxidans SUG 2-2. When resting cells of SUG 2-2 (0.01 mg of protein) were incubated for 10 d at 30 degrees C in 20 ml of 1.6 mM sulfuric acid (pH 2.5) with ferrous sulfate (3%) and mercury-polluted soil (1 g), which contained 7.5 nmol of Hg, approximately 4.1 nmol of mercury was volatilized, indicating that 54% of the total mercury in the soil was volatilized. The amount of mercury volatilized from the soil was dependent on the concentration of Fe2+ added to the medium. When elemental sulfur, sodium tetrathionate, and pyrite were used as an electron donor for the mercury reduction, 16, 2.4 and 0.84%, respectively, of the total mercury added to the solution were volatilized. The optimum pH and temperature for mercury volatilization were 2.5 and 30 degrees C. Approximately 92% of the total mercury in a salt solution (pH 2.5) with resting cells of SUG 2-2 (0.01 mg of protein), ferrous sulfate (3%) and mercury-polluted soil (1 g) was volatilized by further addition of both resting cells and Fe2+ and by incubating for 30 d at 30 degrees C.
Takeuchi
F
F
Administration Center for Environmental Science and Technology, Graduate School of Natural Science and Technology, Okayama University, Tsushima Naka, Japan.
Iwahori
K
K
Kamimura
K
K
Negishi
A
A
Maeda
T
T
Sugio
T
T
D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry / Q000378:metabolism; D008628:Mercury / Q000737:chemistry* / Q000378:metabolism; D020560:Proteobacteria / Q000502:physiology*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D013696:Temperature; D014835:Volatilization
D012989:Soil Pollutants; D007501:Iron; D008628:Mercury