Selenium (Se) is a naturally occurring micronutrient that plays vital roles in human and animal health. However, Se becomes a toxicant to aquatic wildlife at high concentrations in the environment. The phytoremediation technology using plants and associated microbes has been demonstrated as a cost-competitive, sustainable and environmentally sound remediation practice for cleaning up Se-contaminated water, sediment and soil. The soil microbes and plants are capable of bio-transforming inorganic selenate or selenite to volatile organic Se compounds, which transfers Se from soil and water to the atmosphere. In this study we hypothesized that the inoculation of the soil-plant systems with a good Se volatilization bacterial strain Pseudomonas fuscovaginae would significantly enhance biogenic Se volatilization from the soil-plant systems. The laboratory studies showed that the Se volatilization of the soil-Indian mustard system can be significantly enhanced with the soil bacterial inoculation treatment. The inoculation of Pseudomonas fuscovaginae in the soil of Indian mustard (Brassica juncea) significantly (p<0.05) increased Se volatilization by 30.5% compared to the control. The soil-root compartment volatilized approximately 70% of the total Se mass volatilized in the soil-plant system (1.52 µg/pot) during a 7-day experimental period. However, in the soil-rabbitfoot grass (Polypogon monspeliensis) system, the bacterial inoculation treatment did not significantly (p>0.05) affect the levels of Se mass volatilization. The bacterial inoculation treatment significantly (p<0.05) increased Se accumulation in rabbitfoot grass tissues from 27.91±3.49 µg/g in the control to 36.46±3.03 µg/g in the bacterial inoculation treatment, while there was no significant effect on Se accumulation in Indian mustard tissues. This study also indicated that the soil bacterial inoculation could significantly increase rates of Se volatilization in the soil-Indian mustard system that originally has low levels of Se volatilization, but no significant impacts on the soil-rabbitfoot grass system that already has high levels of Se volatilization
|Commitee:||Adegboyega, Nathaniel , McCracken, Vance, Esselman, Elizabeth|
|School:||Southern Illinois University at Edwardsville|
|School Location:||United States -- Illinois|
|Source:||MAI 82/8(E), Masters Abstracts International|
|Subjects:||Environmental science, Soil sciences, Atmospheric sciences, Sedimentary Geology, Aquatic sciences, Systems science|
|Keywords:||Bacterial inoculation, Indian mustard, Pseudomonas fuscovaginae, Rabbitfoot grass, Selenium volatilization, Soil-plant system, Micronutrient , Aquatic wildlife|
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