High-efficiency 99Tc separation from contaminated liquid waste using some anion exchange resins

99Tc removal from contaminated aqueous solution was explored using some commercially available anion exchange resins with various specifications. Various combinations of physicochemical parameters like polymeric network, pore diameter, percent cross-linking, bead size etc. were selected to appraise their impact on 99Tc uptake. Fundamental extraction properties such as effect of solution pH, equilibration time, effect of temperature were determined for obtaining the optimum extraction condition. The resins were characterized using BET, SEM, EDS, XPS, TG, FTIR spectroscopy to decipher the structure-extraction correlation and extraction mechanism. In order to quantify the loading capacity (745 mg/g as maximum) and ascertain the reaction mechanism, non-radioactive surrogate of TcO4-, i.e, ReO4- have been used. ReO4- quantity in solution was measured using UV-Vis spectrophotometry with λmax at 204 nm. 4M HNO3 was found be an effective reagent towards desorption from the loaded resins. The capture performance was found to deteriorate with γ-radiation particularly at higher absorbed dose (500 kGy onwards). Competition studies with most common anions found in ground water as well as soil such as Cl-, NO3-, SO42-, CO32-, PO43- indicate that, even in presence of high concentration (1:10000 molar ratio) of these interfering anions, TcO4- can be selectively extracted by the resins confirming their effectiveness towards the decontamination of real ground water with respect to 99Tc.