Part I: Predicting performance of Purolite A532E resins for remediation of comingled contaminants in groundwater

Current and emerging technologies for the remediation of difficult-to-measure radionuclides at nuclear sites

“…76 No information on A532E Tc uptakes in the same P&T system could be found, although Saslow and coworkers have recorded K d s of >19 800 mL g −1 (>99% resin uptake) in double deionised water containing 200 ppb 99 Tc. 73 This figure remained constant with NO 3 − and SO 4 2− present at concentrations up to 20 mM and 10 mM, respectively, exceeding the levels seen in P&T influent streams (1.61 and 0.60 mM for NO 3 − and SO 4 2− , respectively) between 1 st June 2021 and 30 th May 2022 (data cited in ref. 73).…”

“…76 No information on A532E Tc uptakes in the same P&T system could be found, although Saslow and coworkers have recorded K d s of >19 800 mL g −1 (>99% resin uptake) in double deionised water containing 200 ppb 99 Tc. 73 This gure remained constant with NO 3 high degree of 99 Tc selectivity shows promise for A532E's application at site scales, there is a need for larger pilot trials to support results of simplied laboratory set ups. As the P&T system continues to operate at Hanford, future work by Saslow and coworkers will look at the performance of both A532E and DOWEX 21K with owing groundwater, and scale up models to predict the efficacy with varying P&T inuent chemistry.…”

“…72 Adsorption of technetium, in combination with other contaminants, onto Purolite A532E and DOWEX 21K ion exchange resins is being utilised at the Hanford Site. 73,74 Groundwater P&T inuent streams are pumped into the facility where they are passed through a train of DOWEX columns followed by A532E columns, before being released back into the subsurface. 73,75 DOWEX was rst installed into the P&T system in 2015 and is used primarily for U adsorption.…”

“…73,74 Groundwater P&T inuent streams are pumped into the facility where they are passed through a train of DOWEX columns followed by A532E columns, before being released back into the subsurface. 73,75 DOWEX was rst installed into the P&T system in 2015 and is used primarily for U adsorption. 75 As a result, despite laboratory K d s measuring 1800-19 800 mg L −1 in double deionised water (DDI) containing NO 3 − (90-99% uptake to resin; 0-104 mM NO 3 − ; all with 200 ppb 99 Tc) and >19 800 mL g −1 in DDI containing SO 4 2− (>99% uptake; 0-10 mM SO 4 2− ; all with 200 ppb 99 Tc), 74 resin used in the Hanford P&T columns between 2015 and 2017 showed no Tc adsorption.…”

“…75 As a result, despite laboratory K d s measuring 1800-19 800 mg L −1 in double deionised water (DDI) containing NO 3 − (90-99% uptake to resin; 0-104 mM NO 3 − ; all with 200 ppb 99 Tc) and >19 800 mL g −1 in DDI containing SO 4 2− (>99% uptake; 0-10 mM SO 4 2− ; all with 200 ppb 99 Tc), 74 resin used in the Hanford P&T columns between 2015 and 2017 showed no Tc adsorption. 75 By contrast, Purolite A532E has been chosen for targeted 99 Tc uptake, and is the successor to the A530E resin, a microporous form of the A532E 73 which had a 92.1% 99 Tc removal efficiency in the Hanford P&T facility in 2020. 76 No information on A532E Tc uptakes in the same P&T system could be found, although Saslow and coworkers have recorded K d s of >19 800 mL g −1 (>99% resin uptake) in double deionised water containing 200 ppb 99 Tc.…”