Technetium removal from the aqueous solution using zeolites A and Y containing transition metal ions Co2+ and Zn2+

Abstract

The adsorption properties of two zeolite types, faujasite (NaY, ZnY, CoY) and LTA-4A zeolite (NaA, ZnA, CoA), towards technetium were studied in batch static experiments. The Si/Al ratio, acidity, dealumination, chargebalance cations of zeolite, contact time and temperature determined the adsorption efficiency. The maximum removal efficiency of 98.8% and K (d) value (2.06 x 10(-4) cm(3) g(-1)) was achieved using CoY (zeolite type Y). The kinetics of technetium adsorption followed the pseudo-second order model. The TcO2 adsorption is mainly due to the hydrogen bonds between protons of the zeolitic structural OH groups (Bronsted acid center) and oxygen from the TcO2 (-).