Optimization and evaluation of mixed-bed chemisorbents for extracting fission and activation products from marine and fresh waters

Johnson, Benjamin C.; Santschi, Peter H.; Addleman, R. Shane; Douglas, Matthew; Davidson, Joseph D.; Fryxell, Glen E.; Schwantes, Jon M.

doi:10.1016/j.aca.2011.08.017

Cited by 14 publications

(14 citation statements)

References 28 publications

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“…Dissolved organic carbon (DOC) concentration is another factor which is known to affect the adsorption of elements from solution onto adsorptive materials. − The DOC concentration at WHOI during the flow-through column and flume studies were 1.10 ± 0.06 mg/L and 1.67 ± 0.72 mg/L, respectively. The average DOC background concentration in Sequim Bay seawater is 0.89 ± 0.19 mg/L.…”

Section: Resultsmentioning

confidence: 99%

The Uranium from Seawater Program at the Pacific Northwest National Laboratory: Overview of Marine Testing, Adsorbent Characterization, Adsorbent Durability, Adsorbent Toxicity, and Deployment Studies

Gill

Kuo

Janke

et al. 2016

Ind. Eng. Chem. Res.

124

107

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The Pacific Northwest National Laboratory (PNNL) is evaluating the performance of adsorption materials to extract uranium from natural seawater. Testing consists of measurements of the adsorption of uranium and other elements from seawater as a function of time using flow-through columns and a recirculating flume to determine adsorbent capacity and adsorption kinetics. The amidoxime-based polymer adsorbent AF1, produced by Oak Ridge National Laboratory (ORNL), had a 56-day adsorption capacity of 3.9 ± 0.2 g U/kg adsorbent material, a saturation capacity of 5.4 ± 0.2 g U/kg adsorbent material, and a half-saturation time of 23 ± 2 days. The ORNL AF1 adsorbent has a very high affinity for uranium, as evidenced by a 56-day distribution coefficient between adsorbent and solution of log KD,56day = 6.08. Calcium and magnesium account for a majority of the cations adsorbed by the ORNL amidoxime-based adsorbents (61% by mass and 74% by molar percent), uranium is the fourth most abundant element adsorbed by mass and seventh most abundant by molar percentage. Marine testing at Woods Hole Oceanographic Institution with the ORNL AF1 adsorbent produced adsorption capacities 15% and 55% higher than those observed at PNNL for column and flume testing, respectively. Variations in competing ions may be the explanation for the regional differences. Hydrodynamic modeling predicts that a farm of adsorbent materials will likely have minimal effect on ocean currents and removal of uranium and other elements from seawater when farm densities are <1800 braids/km2. A decrease in uranium adsorption capacity of up to 30% was observed after 42 days of exposure because of biofouling when the ORNL braided adsorbent AI8 was exposed to raw seawater in a flume in the presence of light. No toxicity was observed with flow-through column effluents of any absorbent materials tested to date. Toxicity could be induced with some non-amidoxime based absorbents only when the ratio of solid absorbent to test media was increased to part per thousand levels. Thermodynamic modeling of the seawater−amidoxime adsorbent was performed using the geochemical modeling program PHREEQC. Modeling of the binding of Ca, Mg, Fe, Ni, Cu, U, and V reveal that when binding sites are limited (1 × 10–8 binding sites/kg seawater), vanadium heavily outcompetes other ions for the amidoxime sites. In contrast, when binding sites are abundant, Mg and Ca dominate the total percentage of metals bound to the sorbent.

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Section: Resultsmentioning

confidence: 99%

The Uranium from Seawater Program at the Pacific Northwest National Laboratory: Overview of Marine Testing, Adsorbent Characterization, Adsorbent Durability, Adsorbent Toxicity, and Deployment Studies

Gill

Kuo

Janke

et al. 2016

Ind. Eng. Chem. Res.

124

107

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“…In contrast, other phenomena such as surface precipitation of metal oxides or ternary processes were ascribed to inuence the adsorption efficiency of Cs and some heavy metals from the solution than temperature (increase of which caused about 50% reduction in efficiency) using manganese oxide-Anfezh mixture as chemisorbent. 124 Table 5 and Fig. 3 show the effect of temperature on cesium sorption by various sorbents as reported in the literature.…”

Section: Effect Of Solution Phmentioning

confidence: 94%

“…Nilchi et al [9] and El-Naggar et al [74] also reported similar results with solution temperature ranging from 298 to 338 K [9] . In contrast, other phenomena such as surface precipitation of metal oxides or ternary processes were ascribed to influence the adsorption efficiency of Cs and some heavy metals from the solution than temperature (increase of which caused about 50% reduction in efficiency) using manganese oxide-Anfezh mixture as chemisorbent [124] . In contrast, other phenomena such as surface precipitation of metal oxides or ternary processes were ascribed to influence the adsorption efficiency of Cs and some heavy metals from the solution than temperature (increase of which caused about 50% reduction in efficiency) using manganese oxide-Anfezh mixture as chemisorbent [124] .…”

Section: Effect Of Temperature On Cesium Adsorptionmentioning

confidence: 97%

Influence of adsorption parameters on cesium uptake from aqueous solutions- a brief review

et al. 2015

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Due to rapid population growth, technological advancement and industrial revolution, the rate of generated waste effluents has become a grave concern. Cesium which possesses high fission yield is generally transferred to liquid wastes especially those emanated from the nuclear power plants, reprocessing of spent fuels, nuclear weapon testing and radionuclides production facilities for medical applications etc. Radiocesium ( 137 Cs) is one of the hazardous radionuclides creates adverse effects on human health and environment.Due to its physical (T 1/2 =30.17 y) and chemical characteristics (alkalinity, solubility etc.), it can be easily assimilated by the living organisms. As a result, the removal of cesium from wastewater is imperative from the health point of view. Several techniques are implemented but in recent time, adsorption has been gaining increasing attention to the scientific community owing to a number of reasons. Hence, this paper presents an overview on sorption of cesium from wastewaters. Consequently, several critical parameters such as sorption capacity, percentage efficiency and the influence of several factors on cesium uptake by various adsorbents have been reviewed in details. 6 Adsorption/ ion exchange of cesium ions onto synthesized and natural adsorbentsThis is a method by which a sorbate is removed or accumulated on the immobile solid from its liquid or gaseous surroundings, and usually referred to as liquid-solid interaction.Normally, this process occurs at the phase of the sorbent and so, it is a surface-based phenomenon [40] . Adsorption can take different dimensions, if the process is initiated as a result of weak intermolecular forces (Van der Waals interactions) then it is specifically called physisorption and this force being weak in nature results into reversible adsorption, but if occurs due to the formation of chemical bonds between the molecules of adsorbate and the adsorbent it is known as chemosorption. Ion exchange on the other hand is a reversible chemical process in which an ion from solution exchanges with similarly charged ion attached to the adsorbent, the solid particle [40] . Due to their common features, adsorption and ion exchange are grouped together as sorption processes for effective sequester of toxins from waste/drinking waters [41,42] . Adsorption is recognized as an effective and economic method for the removal of radionuclides compared to the other approaches owing to a number of reasons such as; the ease of design and operation, adsorbate-specificity, better treatment with no/little secondary waste generation, possibility of using at low concentration, high efficient performance, ease of regeneration and reuse, suitability for both batch and column studies, and the availability of the adsorbents [43] . Normally, a good adsorbent must have a large surface area, good macroporous structure and be stable under chemical, radiation and thermal reaction conditions. However, the behaviour and efficiency of adsorbents can also be influenced by the condition of the so...

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“…Mesoporous silica and MnO 2 functionalized with ligands that have a high affinity for actinides, such as hydroxypyridonates, have been shown by Johnson and co-workers to possess notably better actinide sorption ability than conventional actinide sorbents in both ocean and river waters (Figure ). − This metal selectivity could also be controlled by modifying the functionalization of the mesoporous materials: soft Lewis-acidic metals such as Ag were preferred by materials functionalized with thiols, and Cs was preferred by materials functionalized with cyanoferrates. These mesoporous materials were developed to chemically concentrate anthropogenic radionuclides from a matrix containing a large quantity of natural radionuclides such as 40 K, thereby bolstering capabilities for downstream reactor monitoring by gamma spectroscopy.…”

Section: Interface With Synthetic Chemistrymentioning

confidence: 99%

Recent Advances in Nuclear Forensic Chemistry

et al. 2020

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Optimization and evaluation of mixed-bed chemisorbents for extracting fission and activation products from marine and fresh waters

Cited by 14 publications

References 28 publications

The Uranium from Seawater Program at the Pacific Northwest National Laboratory: Overview of Marine Testing, Adsorbent Characterization, Adsorbent Durability, Adsorbent Toxicity, and Deployment Studies

The Uranium from Seawater Program at the Pacific Northwest National Laboratory: Overview of Marine Testing, Adsorbent Characterization, Adsorbent Durability, Adsorbent Toxicity, and Deployment Studies

Influence of adsorption parameters on cesium uptake from aqueous solutions- a brief review

Recent Advances in Nuclear Forensic Chemistry

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