title: The influence of citrate and oxalate on99TcVII, Cs, NpVand UVIsorption to a Savannah River Site soil.
abstract: Batch sorption experiments were conducted with 0.5-50 ppb99Tc,133Cs,237Np and U in the presence and absence of citrate and/or oxalate in a 25 g/L Savannah River Site (SRS) soil suspension. Citrate and oxalate were the ligands of choice due to their relevancy to plant exudates, the nuclides were selected for their wide range of biogeochemical behavior, and the soil from SRS was selected as a model Department of Energy (DOE) site soil. Batch samples were continually mixed on a rotary shaker and maintained at a pH of approximately 5. Analysis via ICP-MS indicated that sorption of237Np increased with ligand concentration compared to baseline studies, as did sorption of99Tc although to a lesser extent. The increased sorption of237Np is proposed to be due to a combination of factors that are dependent on the ligand(s) present in the specific system including, ligand dissolution of the soil by citrate and formation of tertiary soil-oxalate-Np complexes. The increased99Tc sorption is attributed to the dissolution of the soil by the ligands, leading to an increase in the number of available sorption sites for99Tc. Uranium sorption decreased and dissolution of native uranium was also observed with increasing ligand concentration, thought to be a result of the formation of strong U-ligand complexes remaining in the aqueous phase. The majority of these effects were observed at the highest ligand concentrations of 50 mgC/L. No notable changes were observed for the133Cs system which is ascribed to the minimal interaction of Cs+with these organic ligands.
authors.affiliation: Clemson University, Clemson, SC 29634, United States. Electronic address: damontg@clemson.edu.
authors.forename: D
authors.initials: D
authors.lastname: Montgomery
authors.affiliation: Clemson University, Clemson, SC 29634, United States.
authors.forename: K
authors.initials: K
authors.lastname: Barber
authors.affiliation: Clemson University, Clemson, SC 29634, United States.
authors.forename: N
authors.initials: N
authors.lastname: Edayilam
authors.affiliation: South Carolina State University, Orangeburg, SC 29115, United States.
authors.forename: K
authors.initials: K
authors.lastname: Oqujiuba
authors.affiliation: South Carolina State University, Orangeburg, SC 29115, United States.
authors.forename: S
authors.initials: S
authors.lastname: Young
authors.affiliation: South Carolina State University, Orangeburg, SC 29115, United States.
authors.forename: T
authors.initials: T
authors.lastname: Biotidara
authors.affiliation: South Carolina State University, Orangeburg, SC 29115, United States.
authors.forename: A
authors.initials: A
authors.lastname: Gathers
authors.affiliation: South Carolina State University, Orangeburg, SC 29115, United States.
authors.forename: M
authors.initials: M
authors.lastname: Danjaji
authors.affiliation: Clemson University, Clemson, SC 29634, United States.
authors.forename: N
authors.initials: N
authors.lastname: Tharayil
authors.affiliation: Clemson University, Clemson, SC 29634, United States. Electronic address: nmarti3@clemson.edu.
authors.forename: N
authors.initials: N
authors.lastname: Martinez
authors.affiliation: Clemson University, Clemson, SC 29634, United States.
authors.forename: B
authors.initials: B
authors.lastname: Powell
mesh_terms: D000327:Adsorption; D002588:Cesium Radioisotopes / Q000032:analysis*; D019343:Citric Acid / Q000737:chemistry*; D005845:Georgia; D008956:Models, Chemical; D010070:Oxalates / Q000737:chemistry*; D012990:Soil Pollutants, Radioactive / Q000032:analysis; D013667:Technetium / Q000032:analysis*; D014501:Uranium / Q000032:analysis*
chemical_list: D002588:Cesium Radioisotopes; D010070:Oxalates; D012990:Soil Pollutants, Radioactive; D019343:Citric Acid; D014501:Uranium; D013667:Technetium
keywords: Cesium; Ligands; Neptunium; Sorption; Technetium; Uranium