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At the Naturita site in Colorado, USA, groundwaters were sampled and analyzed for chemical composition and by culture and culture-independent microbiological techniques. In addition, sediments were extracted with a dilute sodium carbonate solution to determine quantities of labile uranium within the sediments. Samples from the upgradient portion of the contaminated aquifer, where very little dissolved Fe(II) is found in the groundwater, have uranium content that is controlled by U(VI) adsorption and few metal-reducing bacteria are observed. In the extreme downgradient portion of the aquifer, where dissolved Fe(II) is observed, uranium content of the sediments includes significant quantities of reduced U(IV) and...
At the Naturita site in Colorado, USA, groundwaters were sampled and analyzed for chemical composition and by culture and culture-independent microbiological techniques. In addition, sediments were extracted with a dilute sodium carbonate solution to determine quantities of labile uranium within the sediments. Samples from the upgradient portion of the contaminated aquifer, where very little dissolved Fe(II) is found in the groundwater, have uranium content that is controlled by U(VI) adsorption and few metal-reducing bacteria are observed. In the extreme downgradient portion of the aquifer, where dissolved Fe(II) is observed, uranium content of the sediments includes significant quantities of reduced U(IV) and...
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These datasets are from an incubation experiment with a combination of two minerals (feldspar or amorphous aluminum hydroxide), one living species of bacteria (Escherichia coli), and one added form of C (Arthrobacter crystallopoietes necromass). We characterized the sorptive properties of the minerals with batch sorption experiments using four low molecular weight C substrates (glucose, oxalic acid, glutamic acid, p-hydroxybenzoic acid): this data is provided in the SterileSorptionData file. We then conducted a 3-wk long incubation in serum vials or imaging chambers. In both incubations, feldspar (200 mg) or amorphous aluminum hydroxide (100 mg) was given 1 of 4 different treatments: (1) a water control with autoclaved...
Plant roots and soil microorganisms contain significant quantities of low molecular weight (MW) phosphorylated nucleosides and sugars. Consequently, upon death these can represent a significant input of organic-P to the soil. Some of these organic-P substrates must first be dephosphorylated by phosphatases before being assimilated by the soil microbial community while others can be taken up directly from soil solution. To determine whether sorption or phosphatase activity was limiting the bioavailability of low MW organic-P in soil we compared the microbial uptake and C mineralization of a range of 14C-labeled organic-P substrates [glucose-6-phosphate, adenosine monophosphate (AMP), adenosine diphosphate (ADP) and...
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These datasets are from an incubation experiment with a combination of two minerals (feldspar or amorphous aluminum hydroxide), one living species of bacteria (Escherichia coli), and one added form of C (Arthrobacter crystallopoietes necromass). We characterized the sorptive properties of the minerals with batch sorption experiments using four low molecular weight C substrates (glucose, oxalic acid, glutamic acid, p-hydroxybenzoic acid): this data is provided in the SterileSorptionData file. We then conducted a 3-wk long incubation in serum vials or imaging chambers. In both incubations, feldspar (200 mg) or amorphous aluminum hydroxide (100 mg) was given 1 of 4 different treatments: (1) a water control with autoclaved...
Chemical conditions were perturbed in an aquifer with an ambient pH of 5.9 and wastewater-derived adsorbed zinc (Zn) and phosphate (P) contamination by injecting a pulse of amended groundwater. The injected groundwater had low concentrations of dissolved Zn and P, a pH value of 4.5 resulting from equilibration with carbon dioxide gas, and added potassium bromide (KBr). Downgradient of the injection, breakthrough of nonreactive Br and total dissolved carbonate concentrations in excess of ambient values (excess TCO2) were accompanied by a decrease in pH values and over twentyfold increases in dissolved Zn concentrations above preinjection values. Peak concentrations of Br and excess TCO2 were followed by slow increases...
Categories: Publication; Types: Citation; Tags: metal ion, mobility, sorption
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This USGS data release contains 2013 streamflow, baseflow, and precipitation data from three hydrologically-diverse streams in the United States used to develop a conceptual framework for effectively anticipating water-quality changes resulting from changes in agricultural activities. The framework combined generalized concepts on the movement of water, the environmental behavior of chemicals and eroded soil, and the designed functions of various agricultural activities. The framework addresses the impacts on water quality of a broad range of agricultural chemicals and sediment across a variety of hydrologic settings. • Chesterville Branch near Crumpton, Maryland, (USGS site ID - 01493112) had substantial baseflow...
Understanding uranium (U) sorption processes in permeable reactive barriers (PRB) are critical in modeling reactive transport for evaluating PRB performance at the Fry Canyon demonstration site in Utah, USA. To gain insight into the U sequestration mechanism in the amorphous ferric oxyhydroxide (AFO)-coated gravel PRB, U(VI) sorption processes on ferrihydrite surfaces were studied in 0.01 M Na2SO4 solutions to simulate the major chemical composition of U-contaminated groundwater (i.e., [ SO 4 2 - ] ∼13 mM L−1) at the site. Uranyl sorption was greater at pH 7.5 than that at pH 4 in both air- and 2% pCO2-equilibrated systems. While there were negligible effects of sulfate ligands on the pH-dependent U(VI) sorption...
At the Naturita site in Colorado, USA, groundwaters were sampled and analyzed for chemical composition and by culture and culture-independent microbiological techniques. In addition, sediments were extracted with a dilute sodium carbonate solution to determine quantities of labile uranium within the sediments. Samples from the upgradient portion of the contaminated aquifer, where very little dissolved Fe(II) is found in the groundwater, have uranium content that is controlled by U(VI) adsorption and few metal-reducing bacteria are observed. In the extreme downgradient portion of the aquifer, where dissolved Fe(II) is observed, uranium content of the sediments includes significant quantities of reduced U(IV) and...
A certain amount of wood char or soot in a soil or sediment sample may cause the sorption of organic compounds to deviate significantly from the linear partitioning commonly observed with soil organic matter (SOM). Laboratory produced and field wood chars have been obtained and analyzed for their sorption isotherms of a model solute (phenanthrene) from water solution. The uptake capacities and nonlinear sorption effects with the laboratory wood chars are similar to those with the field wood chars. For phenanthrene aqueous concentrations of 1 μgl−1, the organic carbon-normalized sorption coefficients (log Koc) ranging from 5.0 to 6.4 for field chars and 5.4–7.3 for laboratory wood chars, which is consistent with...
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Cr(VI) contaminated groundwater at Hinkley is undergoing bioremediation using added ethanol as a reductant in a volume of the aquifer defined as the In-situ Reduction Zone (IRZ). This treatment effectively reduces Cr(VI) to Cr(III) which is rapidly sequestered by sorption to aquifer particle surfaces and by co-precipitation within iron or manganese bearing minerals forming in place as reduction proceeds. Successful mitigation of the extant Cr(VI) plume is projected to require 90 to 220 years, at which time ethanol loading will likely cease. This projection assumes that Cr(VI) removal is permanent and that no Cr(III) will oxidize back to Cr(VI) in the event of changing hydrological conditions resulting in oxygen...
    map background search result map search result map Data set used to develop a conceptual framework for effectively anticipating water-quality changes resulting from changes in agricultural activities Aqueous and Solid Phase Chemistry of Sequestration and Re-oxidation of Chromium in Experimental Microcosms with Sand and Sediment from Hinkley, CA Aqueous and Solid Phase Chemistry of Sequestration and Re-oxidation of Chromium in Experimental Microcosms with Sand and Sediment from Hinkley, CA Data set used to develop a conceptual framework for effectively anticipating water-quality changes resulting from changes in agricultural activities