Issues in the Scale-up of Aqueous Biphasic Extraction of Uranium from Contaminated Soils

Chaiko, David J.; Gartelmann, J.; Vojta, Y.; Thuillet, E.; Mertz, Carol J.

doi:10.1007/978-1-4899-1406-4_16

Cited by 4 publications

(6 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Consequently, particle size should be small enough that particle settling due to gravity is low compared to the rate of 1iquidAiquid phase separation. In general, we have found that an upper size limit of about 150-200 ym can be accommodated during continuous, countercurrent extractions (6,7).…”

Section: Introductionmentioning

confidence: 90%

“…We have been evaluating various types of ABE systems for possible applications in the treatment of solid radioactive wastes (1,2), liquid nuclear wastes (3,4), and contaminated soils (5)(6)(7), and in the removal of organics from aqueous salt solutions (8). We have also conducted fundamental studies of the solution microstructure of ABE systems using small angle neutron scattering (SANS) (9).…”

Section: Introductionmentioning

confidence: 99%

“…For example, water-soluble complexants, such as arsenazo I I I , can be used to selectively transfer PuO, or UO, particles from the salt-rich phase into the PEG-rich phase (1,2). In general, the partition coefficients of metal ions, including silicic acid, are in the range of 0.1-0.5 (6,9). However, complex species that possess a significant rotational contribution to the entropy loss of water during solvation, like polymeric plutonium and uranyl carbonate, exhibit extremely low partition coefficients, in the range of 0.001 to 0.01 (9).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Metal separations using aqueous biphasic partitioning systems

Chaiko¹,

Zaslavsky²,

Rollins³

et al. 1996

Self Cite

View full text Add to dashboard Cite

Aqueous biphasic extraction (ABE) processes offer the potential for low-cost, highly selective separations. This countercurrent extraction technique involves selective partitioning of either dissolved solutes or ultrafine particulates between two immiscible aqueous phases. The extraction systems that we have studied are generated by combining an aqueous salt solution with an aqueous polymer solution.We have examined a wide range of applications for ABE, including the treatment of solid and liquid nuclear wastes, decontamination of soils, and processing of mineral ores. We have also conducted fundamental studies of solution microstructure using small angle neutron scattering (SANS). h this chapter we review the physicochemical fundamentals of aqueous biphase formation and discuss the development and scaleup of ABE processes for environmental remediation.

show abstract

Section: Introductionmentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Metal separations using aqueous biphasic partitioning systems

Chaiko¹,

Zaslavsky²,

Rollins³

et al. 1996

Self Cite

View full text Add to dashboard Cite

show abstract

“…These two-phase systems are usually composed of a water-soluble polymer and another component, e.g., another water-soluble polymer, a surfactant, or an inorganic salt. Recently the application of aqueous biphase extraction has broadened to include the separation of ultrafine particle (8)(9)(10)(11)(12)(13)(14) and metal ions (15)(16)(17).…”

Section: Introductionmentioning

confidence: 99%

“…In this system, the particles prefer the top PEG-rich phase under all pH values, which is attributable to the specific polymer-solid interaction through hydrogen bonding between the surface silanol groups and oxygen atoms in the polymer chains. No information has been found in the literature about the partition of silica in the polymer/polymer or polymer surfactant aqueous biphase systems (8)(9)(10)(11)(12)(13)(14)(18)(19)(20). For comparison with our previous studies (19), this work will investigate the partition of silica in the Dex/TX100 and PEG/Dex system.…”

Section: Introductionmentioning

confidence: 99%

Aqueous Biphase Extraction for Processing of Fine Coal

Osseo‐Asare¹

2001

View full text Add to dashboard Cite

Ever-stringent environmental constraints dictate that future coal cleaning technologies be compatible with micron-size particles. This research program seeks to develop an advanced coal cleaning technology uniquely suited to micron-size particles, i.e., aqueous biphase extraction. The partitioning behaviors of silica in the polyethylene glycol (PEG)/dextran (Dex) and dextran/Triton X-100 (TX100) systems have been investigated, and the effects of sodium dodecylsulfate (SDS) and dodecyltrimethylammonium bromide (DTAB) on solid partition have been studied. In both biphase systems, silica particles stayed in the top PEG-rich phase at low pH. With increase in pH, the particles moved from the top phase to the interface, then to the bottom phase. At very high pH, the solids preferred the top phase again. These trends are attributable to variations in the polymer/solid and nonionic surfactant/solid interactions. Addition of ionic surfactants into these two systems introduces a weakly charged environment, since ionic surfactants concentrate into one phase, either the top phase or the bottom phase. Therefore, coulombic forces also play a key role in the partition of silica particles because electrostatic attractive or repulsive forces are produced between the solid surface and the ionic-surfactant-concentrated phase. For the PEG/dextran system in the presence of SDS, SiO 2 preferred the bottom dextran-rich phase above its pH PZC . However, addition of DTAB moved the oxide particles from the top phase to the interface, and then to the bottom phase, with increase in pH. These different behaviors are attributable to the fact that SDS and DTAB concentrated into the opposite phase of the PEG/dextran system. On the other hand, in the dextran/Triton X-100 system, both ionic surfactants concentrated in the top surfactant-rich phase and formed mixed micelles with TX100. Therefore, addition of the anionic surfactant, SDS, moved the silica particles from top phase to the interface or bottom phase. On the other hand, DTAB, a cationic surfactant, attracted the particles to the top phase in the pH range form 4 to 11, where in the DTAB-free system the solids either stayed at the interface or in the bottom phase.

show abstract