Microbial controls on phosphate and lanthanide distributions during granite weathering and soil formation

Taunton, A. E.; Welch, Susan A.; Banfield, Jillian F.

doi:10.1016/s0009-2541(00)00215-1

Cited by 147 publications

(85 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Nevertheless, the present study at least demonstrates that EPS derived from microorganisms can adsorb to metal oxide nanoparticles with specific organic species preferentially adsorbed, modified the surface properties, and changed their stability through the steric barrier derived from organic compounds as well as the electrostatic repulsive forces of the adsorbed ionic species in EPS. In the present experiments, the EPS was released after the incubation in YPD media that contains high P content and thus, the P concentration in the EPS is most likely higher than the one released from microorganisms in subsurface environments except for the microorganisms colonized adjacent to apatite [49]. In typical shallow groundwater with the ionic strength of the order of 10 −2 mol L −1 [14].…”

Section: Effects Of Eps On Aggregation and Sedimentationmentioning

confidence: 65%

Adsorption of Extracellular Polymeric Substances Derived from S. cerevisiae to Ceria Nanoparticles and the Effects on Their Colloidal Stability

et al. 2017

View full text Add to dashboard Cite

Abstract:In order to understand the adsorption preferences of extracellular polymeric substances (EPS) components derived from fungus Saccharomyces cerevisiae on sparingly soluble CeO 2 nanoparticles (CeNPs), the adsorption experiments of the EPS including organic matter with low molecular weight have been performed at pH 6.0 at room temperature (25 ± 1 • C). The subsequent effects of the coating on the dispersibility of CeNPs was systematically measured as a function of time and ionic strength ranging from 1 to 1000 mmol L −1 . Among the EPS and other components, orthophosphate and saccharides preferentially adsorb onto CeNPs, and proteins are the only major N-compounds adsorbing onto the CeNP surfaces. Adsorption of orthophosphate resulted in a dramatic decrease in ζ potential to −40 mV at pH > 5, whereas the EPS adsorption suppressed the deviation of ζ potential within a narrow range (−20-+20 mV) at pHs ranging from 3 to 11. Critical aggregation concentrations (CAC) of an electrolyte (NaCl), inorganic orthophosphate, and EPS solutions are 0.01, 0.14, and 0.25 mol L −1 , respectively, indicating that the EPS adsorption suppresses aggregation of CeNPs by the electrostatic repulsive forces derived from the adsorbed orthophosphate and the steric barrier formed by organic matter on the nanoparticle surfaces. Therefore, the EPS derived from fungus S. cerevisiae can potentially enhance colloidal dispersibility of CeNPs at circumneutral pH.

show abstract

Section: Effects Of Eps On Aggregation and Sedimentationmentioning

confidence: 65%

Adsorption of Extracellular Polymeric Substances Derived from S. cerevisiae to Ceria Nanoparticles and the Effects on Their Colloidal Stability

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Because the groundwater pH at Yucca Mountain is dissimilar to the PZC, both colloidal smectite clays and UOH phases may be stable (van Olphen 1977). In natural environments, rare-earth elements (REE) and thorium are often found associated with phosphate phases intermixed with clays (Taunton et al 2000), similar to that observed with corroded defense high-level-waste glass (DHLWG) (Bates et al 1992;Feng et al 1994;Buck and Bates 1999). However, colloidal transport of thorium and REE is virtually non-existent in unsaturated environments (Wood et al 1997).…”

Section: Introductionmentioning

confidence: 83%

“…Hence, the use of Th and REE analog sites may be inaccurate at times. Studies by Wood et al (1997) (Taunton et al 2000;Wood et al 1997). However, the occurrence of extensive colloid transport of REE and thorium under ambient conditions is rare.…”

Section: Smectite Clay Colloids and Radiocolloidsmentioning

confidence: 99%

Alternative Conceptual Model for Colloid Generation from Commercial Spent Nuclear Fuel

Buck¹,

McNamara²,

Hanson³

2004

View full text Add to dashboard Cite

SummaryYucca Mountain is the Department of Energy's potential geologic repository designed to store and dispose of commercial spent nuclear fuel (CSNF) and other high-level radioactive waste forms. If approved, the site would be the Nation's first geologic repository for disposal of this type of radioactive waste. Yucca Mountain is located in a remote desert on federally protected land within the secure boundaries of the Nevada Test Site in Nye County, Nevada. It is approximately 100 miles northwest of Las Vegas, Nevada. CSNF makes up most of the spent nuclear fuel that requires disposal at Yucca Mountain.The waste-form degradation process models provide technically defensible methods for predicting the long-term capability of the waste forms to control radionuclide release from the immediate vicinity of the waste. These models were provided as eight key feeds to the Total Systems Performance Assessment: radionuclide inventory, in-package chemistry model, cladding degradation model, commercial spent fuel degradation model, high-level waste glass degradation model, other waste-form degradation models, solubility model, and colloid model. Colloid generation from CSNF has been deemed to require further qualification by the present waste-form colloid model. The present colloid model considers the effects of pH and ionic strength on the stability of ideal colloid phases. The location of the boundaries between pH and ionic strength regimes in which colloids are stable or unstable are defined together with the colloid mass concentration in each regime.Colloids may have the potential to transport strongly sorbing radionuclide contaminants in soils and groundwater aquifers (McCarthy and Zachara 1989). Recent studies from the Nevada Test Site (NTS), a site with a similar geology to Yucca Mountain, have indicated the enhanced mobility of plutonium in the saturated zone, albeit in minute quantities, in association with various silicate minerals (Kersting et al. 1999). However, calculated flow rates for the NTS saturated zone are 1000 to 10,000 times higher than those calculated using 36 Cl migration analysis for the proposed Yucca Mountain Repository wastepackage environment under unsaturated conditions (Tompson et al. 2000; CRWMS M&O 1999). Significant colloidal transport of thorium and rare-earth elements (REE), considered to be chemical analogs for plutonium, are postulated to be rare in unsaturated environments (Wood et al. 1997). The current Yucca Mountain models for colloids would have predicted extensive thorium and REE migration, given these phases' association with clay minerals and the colloidal stability of the minerals in both unsaturated and saturated environments.Several studies have pointed to the effect of pore velocity on colloid and particulate migration. An extension of the Ryan and Gschwend (1994) empirical relationship for colloid release indicates that colloid production rates within the waste package should be negligible owing to the predicted low hydraulic conductivities. However, the most important...

show abstract

“…It should be noted that the contents of La and Ce in the studied soils of Perm region remain below the clarke values for the pedosphere despite the soil pollution (Taunton, Welch et al, 2000).…”

Section: Alluvial Soils Of Permmentioning

confidence: 68%

Lanthanides in Soils: X-Ray Determination, Spread in Background and Contaminated Soils in Russia

Vodyanitskiĭ¹,

Savichev²

2012

Geochemistry - Earth's System Processes

View full text Add to dashboard Cite

Microbial controls on phosphate and lanthanide distributions during granite weathering and soil formation

Cited by 147 publications

References 22 publications

Adsorption of Extracellular Polymeric Substances Derived from S. cerevisiae to Ceria Nanoparticles and the Effects on Their Colloidal Stability

Adsorption of Extracellular Polymeric Substances Derived from S. cerevisiae to Ceria Nanoparticles and the Effects on Their Colloidal Stability

Alternative Conceptual Model for Colloid Generation from Commercial Spent Nuclear Fuel

Lanthanides in Soils: X-Ray Determination, Spread in Background and Contaminated Soils in Russia

Contact Info

Product

Resources

About