Arsenic removal from water/wastewater using adsorbents—A critical review

More than 1000× uranium exists in the oceans than exists in terrestrial ores. With nuclear power generation expected to increase over the coming decades, access to this unconventional reserve is a matter of energy security. With origins in the mid-1950s, materials have been developed for the selective recovery of seawater uranium for more than six decades, with a renewed interest in particular since 2010. This review comprehensively surveys materials developed from 2000–2016 for recovery of seawater uranium, in particular including recent developments in inorganic materials; polymer adsorbents and related research pertaining to amidoxime; and nanostructured materials such as metal–organic frameworks, porous-organic polymers, and mesoporous carbons. Challenges of performing reliable and reproducible uranium adsorption studies are also discussed, as well as the standardization of parameters necessary to ensure valid comparisons between different adsorbents.

Materials for the Recovery of Uranium from Seawater

Preparation and applications of ion exchange membranes by radiation-induced graft copolymerization of polar monomers onto non-polar films

Chelating polymers and related supports for separation and preconcentration of trace metals.

Uranium is the main source for nuclear energy but also one of the most toxic heavy metals. The current methods for uranium removal from water present limitations, such as narrow pH operating range, limited tolerance to high salt concentrations, or/and high cost. We show here that a layered sulfide ion exchanger K2MnSn2S6 (KMS-1) overcomes these limitations and is exceptionally capable in selectively and rapidly sequestering high (ppm) as well as trace (ppb) quantities of UO22+ under a variety of conditions, including seawater. KMS-1 can efficiently absorb the naturally occurring U traces in seawater samples. The results presented here reveal the exceptional potential of sulfide-based ion-exchangers for remediating of uranium-containing wastes and groundwater and for extracting uranium from the sea.

Layered Metal Sulfides Capture Uranium from Seawater

To develop insoluble Sn2+ complexes for the preparation of 99mTc radiopharmaceuticals, the adsorption of Sn2+ to macroreticular chelating ion exchange resins having various functional groups was investigated. Among them, a resin containing aminophosphonic acid groups showed a high adsorption capacity for Sn2+, which was bound strongly to the resin by chelation. This macromolecular Sn2+ complex was very stable against hydrolysis and oxidation, and could be applied satisfactorily for the reduction of 99mTc.

Application of a macromolecular Sn(II) complex to the preparation of 99mTc radiopharmaceuticals

Behavior of two macroreticular resins having oxy acids of phosphorus in adsorption and elution of lead ion was studied. One is a phosphonic acid resin based on styrenedivinylbenzene copolymer, and the other is a phosphoric acid resin based on glycidyl methacrylate-divinylbenzene copolymer. Both the resins exhibit the highest selectivity toward lead ion among common divalent metal ions and have high breakthrough capacities comparable to those of sulfonic acid resins in the dynamic uptake of lead ion. In addition, both the presented resins are much superior to sulfonic acid resins in dynamic elution of lead ion.

Behavior of Macroreticular Chelating Resins Having Oxy Acids of Phosphorus in Adsorption and Elution of Lead Ion

Reticulation photochimique d'un film de ce polymere en presence diethylamino-4 benzene diazonium tetrafluoroborate (DAC) et polymerisation cationique de ses composes modeles avec BF 3 produit par photolyse du DAC

Photocationic crosslinking of poly(2,3‐epithiopropyl methacrylate) and photo‐initiated cationic polymerization of its model compounds

Water-solube polymer (PST) containing triethylenetetramine side chain was prepared by the amination of chloromethylated polystyrene with triethylenetetramine in 1,4-dioxane. The polymerization of vinyl monomers was carried out in the water–organic solvent system containing PST and a very small amount of peroxide. The polymerization of methyl methacrylate proceeded smoothly in the presence of both peroxide and PST. It was found that the polymerization was initiated with the radicals generated by the interaction between hydroperoxide and amino groups of PST. 1,4-Dioxane hydroperoxide showed a high activity for the polymerization of methyl methacrylate. The maximum rate of the polymerization was observed at 60°C and in an approximately neutral solution. The addition of suitable amount of Cu(II) accelerated the polymerization of methyl methacrylate. The selective polymerization of vinyl monomers was observed in this system.

Polymerization of vinyl monomers in the water-1,4-dioxane system containing peroxide and water-soluble polymer

Removal of calcium and magnesium ions in a salt solution with the macroreticular chelating resin containing aminomethylphosphonic acid groups was investigated. The resin (RMT-P) exhibited high affinity for calcium and magnesium ions in a salt solution containing 200 g/dm3 of sodium chloride. In the column method, calcium and magnesium ions in a salt solution were preferentially absorbed on the RMT-P, when the salt solution containing 100 mg/dm3 of calcium or magnesium ion was passed through the RMT-P column at a space velocity of 15 h−1. The calcium and magnesium ions adsorbed were eluted by allowing 1 mol/dm3 hydrochloric acid to pass through the column. The recycle of adsorption and elution was found to be satisfactory.

Studies of selective adsorption resins. XXVI. Removal of calcium and magnesium ions in a salt solution with chelating resin containing aminomethylphosphonic acid groups

Hiroaki Egawa

Papers

Application of a macromolecular Sn(II) complex to the preparation of 99mTc radiopharmaceuticals

Behavior of Macroreticular Chelating Resins Having Oxy Acids of Phosphorus in Adsorption and Elution of Lead Ion

Photocationic crosslinking of poly(2,3‐epithiopropyl methacrylate) and photo‐initiated cationic polymerization of its model compounds

Polymerization of vinyl monomers in the water-1,4-dioxane system containing peroxide and water-soluble polymer

Studies of selective adsorption resins. XXVI. Removal of calcium and magnesium ions in a salt solution with chelating resin containing aminomethylphosphonic acid groups