Sorption behavior of pertechnetate ion on Reillex™-HPQ anion exchange resin from Hanford and Melton Valley tank waste simulants and sodium hydroxide sodium nitrate solutions

The batch distribution coefficients (K(d), mL solution/g dry resin) for pertechnetate (TcO(4)(-))between Reillex(TM)-HPQ anion exchange resin and various caustic solutions have been determined. The average K(d) value in 1.5 M NaNO(3)/1.0 M NaOH solution is (262.2 +/- 12.6) mL/g for TcO(4)(-) ranging from 1.0 x 10(-10) M to 5.0 x 10(-4) M. Pertechnetate Kd values were measured in a series of NaOH/NaNO(3) solutions. The series are: 1.00 M NaOH with 0.010 to 5.00 M NaNO(3); 0.100 M NaOH with 0.010 to 5.00 M NaNO(3); 0.100 M NaNO(3) with 0.10 to 5.00 M NaOH; 1.00 M NaNO(3) with 0.10 to 5.00 M NaOH; 1.50 M NaNO(3) with 0.10 to 5.00 M NaOH; 3.50 M NaNO(3) with 0.10 to 5.00 M NaOH. The K(d) values are described by the following equation. K(d) = {394 +/- 9/(0.120 +/- 0.009) + [NO(3)(-)]} + {132 +/- 27/(0.477 +/- 0.162) + [NO(3)(-)]} [OH(-)] This equation was used to predict the K(d) values for a series of tank waste simulants. The predicted K(d) values are different from the measured values with an average absolute difference of (29 +/- 10)%. Pertechnetate K(d) values for 101-SY, 103-SY, DSS, DSSF-2.33, DSSF-5, DSSF-7, 101-AW, and Melton Valley simulants have been determined as a function of time. A first order approach to equilibrium is observed. The Kd values at two hours are (1066 +/- 45), (870 +/- 102), (346 +/- 18), (296 +/- 15), (245 +/- 6), (209 +/- 11), (218 +/- 5), and (167 +/- 5) mL/g, respectively.