SORPTION BEHAVIOR OF PERTECHNETATE ION ON REILLEX(TM)-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 (TcO4-)between Reillex(TM)-HPQ anion exchange resin and various caustic solutions have been determined. The average K-d value in 1.5 M NaNO3/1.0 M NaOH solution is (262.2 +/- 12.6) mL/g for TcO4- ranging from 1.0 x 10(-10) M to 5.0 x 10(-4) M. Pertechnetate Kd valu es were measured in a series of NaOH/NaNO3 solutions. The series are: 1.00 M NaOH with 0.010 to 5.00 M NaNO3; 0.100 M NaOH with 0.010 to 5.0 0 M NaNO3; 0.100 M NaNO3 with 0.10 to 5.00 M NaOH; 1.00 M NaNO3 with 0 .10 to 5.00 M NaOH; 1.50 M NaNO3 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 follow ing equation. K-d = {394 +/- 9/(0.120 +/- 0.009) + [NO3-]} + {132 +/- 27/(0.477 +/- 0.162) + [NO3-]} [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 absolu te difference of (29 +/- 10)%. Pertechnetate K-d values for 101-SY, 10 3-SY, DSS, DSSF-2.33, DSSF-5, DSSF-7, 101-AW, and Melton Valley simula nts 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.