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

Journal Article · Thu Jun 01 00:00:00 EDT 2023 · Journal of Environmental Chemical Engineering (Online)

DOI:https://doi.org/10.1016/j.jece.2023.109618· OSTI ID:1969012

Saslow, Sarah A.  ^[1]; Levitskaia, Tatiana G.  ^[1]; Cordova, Elsa ^[1]; Avalos, Nancy M. ^[1]; Boglaienko, Daria ^[1]; Fang, Yilin ^[1]; Song, Xuehang ^[1]; Lawter, Amanda R. ^[1]; Emerson, Hilary P. ^[1]; Szecsody, James E. ^[1]; Johnson, Christian D.  ^[1]; Pearce, Carolyn I. ^[1]; Freedman, Vicky L. ^[1]; Mackley, Robert D. ^[1]

---

1. Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

Ion exchange (IX) resins are used in pump-and-treat (P&T) facilities to remove soluble groundwater contaminants. However, natural anions present at concentrations orders of magnitude higher than contaminants can compete for IX sites and impact resin lifecycles. Here, the Hanford Site’s 200 West Area P&T facility (Washington State, USA) was selected as a case study because it currently uses two IX resins: Purolite® A532E (A532E) to remove pertechnetate (TcO₄^-) and DOWEX 21K (DOWEX) to remove uranium from groundwater. Nitrate (NO₃^-), sulfate (SO₄^2-), chloride (Cl^-), and carbonate (CO₃^2-) anions have been identified to potentially compete for A532E and DOWEX IX sites. Hanford-relevant anion groundwater concentrations were used to design a series of laboratory-scale batch experiments to evaluate the impact of competing anions on resin performance and potential kinetic effects. These data are then modeled to obtain Cl--normalized equilibrium exchange coefficients (K) needed to predict IX resin performance. The work is presented in two parts, with IX performance evaluated for A532E in Part I and DOWEX in Part II. Part I results demonstrate that TcO₄^- uptake is not impacted by NO₃^-, SO₄^2-, Cl^-, CO₃^2- (as HCO₃^-) and U(VI) carbonate anions, with K_TcO4-/Cl- > 4,000, likely due to the high selectivity of A532E trihexylammonium sites for the large, weakly hydrated TcO₄^- anion. Other anion K values were K_NO3-/Cl- = 20, K_SO4--/Cl- = 0.2, K_HCO3-/Cl- = 0.09, K_U/Cl- = 370–1000. These K values provide conservative parameters for predicting A532E performance, and demonstrate that, under these test conditions, A532E will remove TcO₄^- from current and future influent streams to meet groundwater treatment objectives.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC05-76RL01830
• OSTI ID: 1969012
• Report Number(s): PNNL-SA-178092; TRN: US2313362
• Journal Information: Journal of Environmental Chemical Engineering (Online), Vol. 11, Issue 3; ISSN 2213-3437
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
pump-and-treat
uranium
technetium
anion exchange
Hanford