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Mixed nitrate and metal contamination influences operational speciation of toxic and essential elements
Environmental contamination constrains microbial communities impacting diversity and total metabolic activity. The former S-3 Ponds contamination site at Oak Ridge Reservation (ORR), TN, has elevated concentrations of nitric acid and multiple metals from decades of processing nuclear material. To determine the nature of the metal contamination in the sediment, a three-step sequential chemical extraction (BCR) was performed on sediment segments from a core located upgradient (EB271, non-contaminated) and one downgradient (EB106, contaminated) of the S-3 Ponds. The resulting exchangeable, reducing, and oxidizing fractions were analyzed for 18 different elements. Comparison of the two cores revealed changes in operational speciation for several elements caused by the contamination. Those present from the S-3 Ponds, including Al, U, Co, Cu, Ni, and Cd, were not only elevated in concentration in the EB106 core but were also operationally more available with increased mobility in the acidic environment. Other elements, including Mg, Ca, P, V, As, and Mo, were less operationally available in EB106 having decreased concentrations in the exchangeable fraction. Here, the bioavailability of essential macro nutrients Mg, Ca, and P from the two types of sediment was determined using three metal-tolerant bacteria previously isolated from ORR. Mg and Ca were available from both sediments for all three strains; however, P was not bioavailable from either sediment for any strain. The decreased operational speciation of P in contaminated ORR sediment may increase the dependence of the microbial community on other pools of P or select for microorganisms with increased P scavenging capabilities. Hence, the microbial community at the former S-3 Ponds contamination site may be constrained not only by increased toxic metal concentrations but also by the availability of essential elements, including P.
Stalk sap nitrate test as a potential tool for nitrogen fertilizer recommendations for maize
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Structural and computational examination of hydrogen-bonding between the C-H bonds of phenylphosphates and nitrate ions
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Isolation of anhydrous tetrabutylphosphonium lanthanide hexa- and penta-nitrates from ionic liquids
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Frequency-Domain Hot-Wire Measurements of Molten Nitrate Salt Thermal Conductivity
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Improved SiGr/NCM523 Cycling via Triethyl Phosphate-Solubilized Lithium Nitrate Electrolyte
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Identifying the Molecular Properties that Drive Explosive Sensitivity in a Series of Nitrate Esters
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