Carbonate dramatically affects the adsorption of uranium (U(VI)) onto iron hydroxides and its mobility in the natural environment. Batch tests, zeta potential measurements, and Fourier transform infrared (FTIR) spectroscopic studies were utilized to characterize the nature of U(VI) adsorption on ferrihydrite. Adsorption isotherms demonstrated that carbonate had a negative effect on U(VI) adsorption on ferrihydrite at pH > 6. Zeta potential measurements indicated that U(VI) was adsorbed as a cationic species (SO-UO2+) in the absence of carbonate and as anionic U(VI) complexes in the presence of carbonate at neutral pH. FTIR spectroscopic measurement of adsorbed U(VI) suggested that it was retained as uranyl carbonate complexes in the presence of carbonate. An increase in carbonate concentration caused a shift in the antisymmetric stretching vibration of the uranyl (UO2(2+)) U-O bond toward lower wavenumbers, which indicated an increasing carbonate effect in the adsorbed uranyl carbonate complexes. The adsorbed U(VI) species were successfully incorporated into a surface complexation model to describe the adsorption of U(VI) by ferrihydrite from artificial solutions and contaminated water.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/es034166m | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Soybean tolerance to waterlogging is achieved by detoxifying root lactate via lactate dehydrogenase in leaves and metabolizing malate and succinate.
Plant Physiol Biochem
January 2025
Botany Department, Federal University of Pelotas, Capão Do Leão, RS, 96160-000, Brazil.
Waterlogging is a significant stressor for crops, particularly in lowland regions where soil conditions exacerbate the problem. Waterlogged roots experience hypoxia, disrupting oxidative phosphorylation and triggering metabolic reorganization to sustain energy production. Here, we investigated the metabolic aspects that differentiate two soybean sister lines contrasting for waterlogging tolerance.
View Article and Find Full Text PDFPectin/gelatin-based bionanocomposite containing modified graphene quantum dots and carnauba wax as functional fillers for food packaging applications.
J Food Sci
January 2025
Nutrition Research Center, Department of Food Science and Technology, Faculty of Nutrition and Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.
Alternatives to nonbiodegradable synthetic plastics for food packaging include films made from biopolymers that are nontoxic and environment-friendly. In this study, carnauba wax (CW) and nitrogen-doped graphene quantum dots (NG) as functional additives were utilized in the production of pectin/gelatin (PG) film. NG was synthesized through the microwave method, using acetic acid as the carbon source, giving size, and zeta potential of 1.
View Article and Find Full Text PDFSupercritical fluid extrusion of pea flour and pea protein concentrate: Effects on off-flavor removal and sensory improvement.
J Food Sci
January 2025
Department of Food Science, Cornell University, Ithaca, New York, USA.
This study was intended to provide a novel process that fills a knowledge gap in relation to the enhancement of pulses utilization. The primary goal was to develop an experimental framework for using a high-pressure supercritical fluid extruder (SCFX) as a continuous bioreactor to produce off-flavor reduced and functionally superior pulse flours and protein concentrates in a single step. The current study focused on using SCFX processing to remove off-flavor from pulse flour and protein concentrates, enhancing the quality, acceptability, and marketability of pulse-based products.
View Article and Find Full Text PDFSecondary Coordination Effects of Adjacent Metal Center in Metal-Nitrogen-Carbon Improve Scaling Relation of Oxygen Electrocatalysis.
J Phys Chem Lett
January 2025
Hefei National Research Center for Physical Sciences at the Microscale, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China.
Heterogenous single-atom catalysts (SACs) are reminiscent of homogeneous catalysts because of the similarity of structural motif of active sites, showing the potential of using the advantage of homogeneous catalysts to tackle challenges in hetereogenous catalysis. In heterogeneous oxygen electrocatalysis, the homogeneity of adsorption patterns of reaction intermediates leads to scaling relationships that limit their activities. In contrast, homogeneous catalysts can circumvent such limits by selectively altering the adsorption of intermediates through secondary coordination effects (SCEs).
View Article and Find Full Text PDFZirconium(IV)-Catalysed Hydrosilylation of Organic Carbonates and Polycarbonates Household Wastes into Alcohol Derivatives.
Chemistry
January 2025
Centre CEA Paris-Saclay: Commissariat a l'Energie Atomique et aux Energies Alternatives Centre de Saclay, IRAMIS Institute, CEA - Saclay, 91190, Gif-Sur-Yvette, FRANCE.
The Schwartz's reagent Cp2Zr(H)Cl is a well known stoichiometric reagent for the reduction of unsaturated organic molecules but it has rarely been used in catalytic transformations. Herein, we describe the reduction of a variety of organic carbonates using the catalyst Cp2Zr(H)Cl in combination with Me(MeO)2SiH (DMMS) as reductant. This method was further applied to the reductive depolymerization of some polycarbonate materials and yielded silylated alcohols and diols in mild conditions.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!