Studies on sorption of uranium on chitin: a solid-state extractant application for removal of uranium from ground water Beena Sunilkumar • G. Chakrapani Received: 1 September 2014 / Published online: 29 October 2014 Ó Akade ´miai Kiado ´, Budapest, Hungary 2014 Abstract Studies were carried out to remove uranium from aqueous systems based on the solid phase extraction of uranium by powdered chitin. The effects of various param- eters like pH, contact time, and amount of chitin for quan- titative sorption of uranium on chitin have been studied. The sorption studies with spiked water samples and natural ground water samples showed that uranium was easily sor- bed onto powdered chitin between pH 3 and 6. The effects of various cations and anions, which are present in the water samples, were studied. The method is simple, fast and environmental friendly and it is unaffected by the other ions present in the natural waters. The accuracy of the method was evaluated by applying the present method on ground water samples containing uranium in the range of 100–2,200 lg/L. The uranium remained in water samples is \ 20 lg/L after treatment with chitin, which is below the AERB limits given for uranium in drinking water. The values are an average of five replicate measurements, with an RSD of ±10 lg/L at 100 lg/L uranium in water samples. Keywords Chitin Á Uranium Á Sorption Á Water samples Introduction Chitin is a natural bio-sorbent, having high molecular weight, which is obtained in large quantities from crustacean shells, which are waste products of sea food processing industries. Chitin and its derivatives are impor- tant natural polymers because of their unique combination of properties like biodegradability, biocompatibility and bioactivity, in addition to attractive physical and mechani- cal properties [1]. Chitin and its derivatives chitosan and chitin phosphate have a variety of applications in biomed- ical products, cosmetics, food processing. These products have found good application for removal of dyes and heavy metal impurities in waste waters [2]. Many other materials like activated carbon, fly ash, silica gel, zeolites, lignin, seawood, clay materials, agricultural wastes etc. have also been extensively studied for the removal of pollutants from aqueous streams, especially for heavy metals like Cd, Cr, Hg, Pb [3, 4]. The powdered activated carbon has been used extensively for removal of U, REE and trace elements [5– 7]. Sorption of high field strength elements like Zr, Hf, Mo, W, Nb, Ta in geological samples were studied by powdered chitin [8, 9]. Literature survey shows that much of earlier work on sorption of uranium has been carried out using derivatives of chitin like chitosan, chitosan phosphate and chitin phosphate for recovery of uranium from sea water and mine water [10]. Cross linked chitosan resins has been used for the enrichment of uranium from sea water in many countries. [11, 12]. Chitin based renewable sponge net- works from A. aerophoba were used as a sorption material for uranium from aqueous solutions, and this sponge chitin gave a reported adsorption capacity of 280 mg/g. [13]. Recently uranium adsorption studies were carried out on hydrothermal carbon produced by chitosan with an adsorption capacity of 273 mg/g [14]. Keeping in view of all these parameters, the authors carried out the basic studies to optimise the parameters to remove uranium from natural water systems by using the powdered bio-sorbent chitin. The present investigation was undertaken to obtain B. Sunilkumar (&) Á G. Chakrapani Chemistry Laboratory, Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Hyderabad 500 016, India e-mail: beenasunilkumar@gmail.com G. Chakrapani e-mail: chakrapanigotur57@gmail.com 123 J Radioanal Nucl Chem (2014) 302:1489–1493 DOI 10.1007/s10967-014-3715-8