Behaviour of uranium in elemental iron and hydroxyapatite reactive barriers: column experiments

Simon, Franz‐Georg; Biermann, Vera

doi:10.1016/s0927-5215(05)80008-6

Cited by 4 publications

(3 citation statements)

References 31 publications

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“…[] and Dunham‐Cheatham et al . []), and abiotic reactions including adsorption and mineral precipitation [ Morrison and Spangler , ; Naftz et al ., ; Gabriel et al ., ; United States Environmental Protection Agency ( USEPA ), ; Simon and Biermann , ; Wellman et al ., ; Hiemstra et al ., ]. Among these approaches, abiotic precipitation has received considerable attention due to its success in uranium removal from soil and groundwater [ Arey et al ., ; USEPA , ; Fuller et al ., ; Simon et al ., ].…”

Section: Introductionmentioning

confidence: 99%

Pore‐scale evaluation of uranyl phosphate precipitation in a model groundwater system

Fanizza

Yoon

Zhang

et al. 2013

Water Resources Research

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[1] The abiotic precipitation of uranium (U(VI)) was evaluated in a microfluidic pore network (i.e., micromodel) to assess the efficacy of using a phosphate amendment to immobilize uranium in groundwater. U(VI) was mixed transverse to the direction of flow with hydrogen phosphate (HPO 4 2À ), in the presence or absence of calcium (Ca 2þ ) or sulfate (SO 4 2À ), in order to identify precipitation rates, morphology and types of minerals formed, and effects of mineral precipitates on pore blockage. Precipitation occurred over the time scale of hours to days. Relative to when only U(VI) and HPO 4 2À were present, precipitation rates were 2.3 times slower when SO 4 2À was present, and 1.4 times faster when Ca 2þ was present; larger crystals formed in the presence of SO 4 2À. Raman backscattering spectroscopy and micro-X-ray diffraction results both showed that the only mineral precipitated was chernikovite, UO 2 HPO 4 Á 4H 2 O; energy dispersive X-ray spectroscopy results indicate that Ca and S are not incorporated into the chernikovite lattice. A pore-scale model was developed, and simulation results of saturation ratio (SR ¼ Q/K sp ) suggest that chernikovite is the least thermodynamically favored mineral to precipitate (0 < SR < 1) compared to uranyl hydrogen phosphate and Na-autunite (13 < SR < 40), and uranyl orthophosphate and Ca-autunite (when Ca 2þ is present; SR > 10 5 ). Fluorescent tracer studies and laser confocal microscopy images showed that densely aggregated precipitates blocked pores and reduced permeability. The results suggest that uranium precipitation with phosphate as chernikovite is rapid on the time scale of remediation for the conditions considered and can block pores, alter fluid flow paths, and potentially limit mixing and precipitation.

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Section: Introductionmentioning

confidence: 99%

Pore‐scale evaluation of uranyl phosphate precipitation in a model groundwater system

Fanizza

Yoon

Zhang

et al. 2013

Water Resources Research

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“…Shown, that 4As-TiO 2 also adsorbed calcium cations, but adsorption values of Ca 2+ are lower than adsorption values of strontium in the same conditions. [20,21]. Colloidal compounds of calcium with phosphate anions are capable of adsorption of strontium, uranium, and some other heavy and transition metals on their surface [21].…”

Section: Influence Of Chemical Composition Of Scale On 90 Sr Adsorptionmentioning

confidence: 99%

“…[20,21]. Colloidal compounds of calcium with phosphate anions are capable of adsorption of strontium, uranium, and some other heavy and transition metals on their surface [21].…”

Section: Influence Of Chemical Composition Of Scale On 90 Sr Adsorptionmentioning

confidence: 99%

90Sr adsorption from the aquatic environment of Chornobyl exclusion zone by chemically enhanced TiO2

Mironyuk¹,

Mykytyn²,

Kaglyan³

et al. 2020

Nucl. Phys. At. Energy

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This paper describes the testing of titanium dioxide, chemically modified by arsenate groups, as an adsorbent of 90Sr from the component of aquatic ecosystems of the Chornobyl exclusion zone. It is shown, that the chemical composition of the aquatic environment impacts 90Sr adsorption. The 4As-TiO2 adsorbent reduces the activity of some samples by almost 100 %, which indicates selectivity and high adsorption capacity of the adsorbent in relation to 90Sr. In some experiments, this value reached 100 %, and the activity was reduced to the level of the maximum permissible 90Sr concentration.

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Long-term performance of reactive materials in PRBs for uranium remediation

Biermann

Simon

Csővári³

et al. 2006

Uranium in the Environment

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Behaviour of uranium in elemental iron and hydroxyapatite reactive barriers: column experiments

Cited by 4 publications

References 31 publications

Pore‐scale evaluation of uranyl phosphate precipitation in a model groundwater system

Pore‐scale evaluation of uranyl phosphate precipitation in a model groundwater system

90Sr adsorption from the aquatic environment of Chornobyl exclusion zone by chemically enhanced TiO2

Long-term performance of reactive materials in PRBs for uranium remediation

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