Recovery and pre-concentration of uranium from secondary effluent using novel resin

Abstract: Ion exchange technology remains the workhorse of various chemical, petrochemical, food, power, and pharmaceutical industries. The success of ion exchange process depends literally on understanding of its basic principles and applying them in a way suiting the nature of the treated feed. This chapter reviews the basic fundamentals and key components of ion exchange process taking into consideration the latest progress taking place in the field. The variation in the ion exchange materials, their nature, forms, and functions are reviewed. The kinetics, sorption equilibrium, operating modes, and engineering configurations for ion exchange processes are also discussed. A brief encounter for the various applications utilizing ion exchange processes is also presented.

Abstract: Research and technological developments are being pursued vigorously all over the world to reduce the cost of desalinated water. Thermal and membrane-based desalination processes are very well known and plants are being operated to augment the demand of fresh water essential for drinking in water-scarce countries and to sustain the industrial processes. Any further improvement in energy reduction can only be marginal considering the complexity of the desalination system. The alternative approach is to add value by recovering edible salt, rare and valuable metals, such as caesium, titanium, uranium and vanadium, from the reject brine streams. In this regard, a novel polymeric chelating resin was designed and developed in Desalination Division, BARC laboratory with significant potential for this achievement. In this paper, the characteristics and potential of the resin have been described for the recovery of valuable elements based on experimental findings.

Abstract: “In-House” resin Polyacrylhydroxamic acid (PHOA) has been synthesized and utilized targeting ground water remediation; recovery of uranium from low concentration aqueous solution e.g., mining activities related water, flooding of excavated or deplumed areas, nuclear plant washed effluent and process generated effluents in nuclear plant during front-end as well as back-end treatment. In the present study, treatment of field effluent containing heavy metals and radio-nuclides from contaminated mining sites reflected preference for uranium with respect to manganese. The specific complexation between the extractant and metal ion especially uranium provides high distribution co-efficient (Kd) for uranium (Kd,U = 1,450 mL/g from inlet of Effluent Treatment Plant (ETP) and Kd,U = 74,950 mL/g for synthetic solution) compared to high level impurity (1,000 times higher concentration) of manganese (Kd,Mn = 111 mL/g from inlet of ETP and Kd,Mn = 10,588 mL/g for synthetic solution). The “In-House” resin showed significant extractability (70–95% elution efficiency) and indicates a possibility of selective removal/recovery of the valuable metal ions even from secondary sources. As a specialty, resin can be regenerated and reused.

Abstract: The Jekyll and Hyde nature of iron and uranium loaded “IN-HOUSE’ resin viz., Polyacrylamide hydroxamic acid (PAAHA) has been characterized by FT-IR, SEM, Mossbauer spectroscopy, EDXRF and magnetization measurements techniques. Among all Mossbauer spectra and magnetization properties indicates supportive documents of characteristic special acquaintance nature of iron w.r.t accumulated U within the matrix even after loading of Fe in vast.

Abstract: Attrition is erosion by friction, i.e., wearing down of particles by friction due to water. Powdery materials such as titanium dioxide (TiO2), a well known sorbent, suffers from attrition loss during metal ion recovery, mainly during regeneration of TiO2 for reuse. To minimize the inorganic sorbent (TiO2) loss, inorganic–organic composite (hybrid) sorbent was prepared from a radical initiated solution polymerization of acrylamide and freshly prepared titanium dioxide. Uranium uptake has been compared with titanium dioxide (freshly prepared), TiO2–polymer composite and virgin polymer. The potential of this composite sorbents for the uranium recovery was ascertained.

Abstract: Hydroxylamine derivatives of cross-linked poly(acrylonitriles), so-called poly(acrylamidoxime) resins, are suitable for the accumulation of uranium from natural seawater of pH = 8.1–8.3. Depending on the method of manufacture, these sorbers yield excellent uranium loadings up to some thousand ppm which roughly equals the average uranium content of actually explored uranium ores. The rate of uranium uptake, which is 5-30 ppm/d at room temperature, increases with increasing temperature of seawater. Uranium can be eluted by 1 M HCl with an elution efficiency of more than 90%. Owing to a certain instability of the uranium binding groups in acid eluants, the uranium uptake decreases with increasing number of sorption-elution cycles. Hydroxylamine derivatives of poly(acrylonitrile) are shown to contain simultaneously at least two kinds of functional groups: open-chain amidoxime groups which are stable and cyclic imidoxime groups which are unstable in 1 M HCl. Experimental evidence is presented that the...

Abstract: Major quantities of uranium find use as nuclear fuel in nuclear power reactors. In view of the extreme toxicity of uranium and consequent stringent limits fixed by WHO and various national governments, it is essential to remove uranium from nuclear power reactor effluents before discharge into environment. Ion imprinted polymer (IIP) materials have traditionally been used for the recovery of uranium from dilute aqueous solutions prior to detection or from seawater. We now describe the use of IIP materials for selective removal of uranium from a typical synthetic nuclear power reactor effluent. The IIP materials were prepared for uranyl ion (imprint ion) by forming binary salicylaldoxime (SALO) or 4-vinylpyridine (VP) or ternary SALO-VP complexes in 2-methoxyethanol (porogen) and copolymerizing in the presence of styrene (monomer), divinylbenzene (cross-linking monomer), and 2,2'-azobisisobutyronitrile (initiator). The resulting materials were then ground and sieved to obtain unleached polymer particles. Leached IIP particles were obtained by leaching the imprint ions with 6.0 M HCl. Control polymer particles were also prepared analogously without the imprint ion. The IIP particles obtained with ternary complex alone gave quantitative removal of uranyl ion in the pH range 3.5-5.0 with as low as 0.08 g. The retention capacity of uranyl IIP particles was found to be 98.50 mg/g of polymer. The present study successfully demonstrates the feasibility of removing uranyl ions selectively in the range 5 microg - 300 mg present in 500 mL of synthetic nuclear power reactor effluent containing a host of other inorganic species.

Abstract: The recovery of uranium from nuclear industrial effluent has been studied using laboratory column and polymeric ion exchange resin. The industrial effluent, at pH around 10, contains uranium (40 mg/L), ammonium (80 g/L) and carbonate (170 g/L) and cannot be discharged without previous treatment. Uranium is in the form of uranyl quadrivalent complex anions [UO2(CO3)3] 4 . The resin IRA 910 U was employed for its specific application for uranium extraction. Adsorption was carried out at flow rate of 1.0, 2.0, and 5.0 mL/min, which corresponds to a retention time of 10, 5.0 and 2.5 min, respectively. The use of ion the exchange technique makes the recovery of more than 98% of the uranium possible. Elution was carried out with ammonium carbonate solutions and also with the diluted effluent. The eluate contained uranium ranging from 2.4 to 2.7 g/L. The solution eluate might be recycled back into the process with the advantage of saving this valuable metal. 2005 Published by Elsevier Ltd.

Abstract: Despite the low concentration of uranium in seawater (3.3 ppb), a special emphasis has been placed on its recovery. Although the concentration is low, it has been estimated that the world's oceans contain about 4 × 109 tons of uranium—theoretically an unlimited supply of nuclear fuel. Adsorption has been considered to be a technically feasible procedure for a uranium recovery process with regard to economic and environmental impacts. The present paper restricts its coverage to those applications using chelating polymeric resins containing amidoxime groups as the most promising adsorbent. ∗Dedicated to Prof. Iwao Tabushi for his endeavors in the field of “recovery of uranium from seawater.”