Some radiochemical studies on the adsorption behaviour of molybdenum-99 on silver-coated carbon granules and activated carbon

Abstract

The adsorption behaviour of Mo tagged with⁹⁹Mo (in the form of molybdate and phosphomolybdate) and^99mTc as pertechnetate werw measured using silver-coated carbon, activated carbon and an equal mixture of both at HNO₃ concentrations ranging from 0.01 to 2M. It was found that, on activated carbon and silver-coated carbon, molybdate and phosphomolybdate have high absorption values at 0.01 M HNO₃ and activated carbon has a high adsorption value for^99mTcO ⁻₄ at the same low acid concentration. The capacity of Ag−C, C and Ag−C/C for molybdate at pH 2–3 has been found to be 240 mg MoO₃/g, 320 mg MoO₃/g and 360 mg MoO₃/g, respectively. For phosphomolybdate, the capacity of the same substrates at pH2–3 was found to be 550 mg MoO₃/g, 650 mg MoO₃/g and 1000 mg MoO₃/g, respectively. These results indicate that with phosphomolybdate the capacity of Mo on the substrates is 2–3 times higher than with molybdate.