Dissolution-Desorption Dynamics of Strontium During Elution Following Evaporation: pH and Ionic Strength Effects
Radioactive strontium-90 (<sup>90</sup>Sr<sup>2+</sup>) is a fission byproduct of uranium and plutonium production, and therefore understanding its environmental fate is of particular importance for predicting the evolution of long-term risk from historical releases. The nonr...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-05-01
|
| Series: | Water |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4441/12/5/1461 |
| _version_ | 1797567408468131840 |
|---|---|
| author | William C. Weaver Tohren C. G. Kibbey Charalambos Papelis |
| author_facet | William C. Weaver Tohren C. G. Kibbey Charalambos Papelis |
| author_sort | William C. Weaver |
| collection | DOAJ |
| description | Radioactive strontium-90 (<sup>90</sup>Sr<sup>2+</sup>) is a fission byproduct of uranium and plutonium production, and therefore understanding its environmental fate is of particular importance for predicting the evolution of long-term risk from historical releases. The nonradioactive strontium cation, Sr<sup>2+</sup>, is a chemical analog for <sup>90</sup>Sr<sup>2+</sup> that is often used in studies designed to understand the environmental behaviors of <sup>90</sup>Sr<sup>2+</sup>. The focus of this work was on understanding the dynamics of remobilization of strontium following evaporation to dryness in porous media. Evaporation is ubiquitous in the unsaturated zone, and has the potential to significantly impact the dynamics of transport by driving adsorption or precipitation on solid surfaces. For this work, a series of transport experiments were conducted examining the behavior of strontium over a range of pH values, ionic strengths, and concentrations. Saturated transport experiments were conducted, followed by experiments designed to examine the release and transport following evaporation to dryness. Results show increasing saturated retardation with increasing pH, decreasing ionic strength, and decreasing concentration, with the concentration exhibiting the strongest effect. Breakthrough curves at low concentrations were also found to be consistent with significant rate-limited desorption. Remobilization elution curves measured following evaporation to dryness exhibited the high initial effluent concentrations, exceeding the influent strontium concentration, most likely caused by the initial dissolution and accumulation of strontium by the advancing solution. Concentrations at later times were found to be largely consistent with the dynamics of saturated transport for the systems studied. |
| first_indexed | 2024-03-10T19:41:27Z |
| format | Article |
| id | doaj.art-179961a6cfdc4a1fb97e5da43ad675e9 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-10T19:41:27Z |
| publishDate | 2020-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-179961a6cfdc4a1fb97e5da43ad675e92023-11-20T01:09:11ZengMDPI AGWater2073-44412020-05-01125146110.3390/w12051461Dissolution-Desorption Dynamics of Strontium During Elution Following Evaporation: pH and Ionic Strength EffectsWilliam C. Weaver0Tohren C. G. Kibbey1Charalambos Papelis2Department of Civil Engineering, New Mexico State University, Las Cruces, NM 88003, USASchool of Civil Engineering and Environmental Science, University of Oklahoma, Norman, OK 73019, USADepartment of Civil Engineering, New Mexico State University, Las Cruces, NM 88003, USARadioactive strontium-90 (<sup>90</sup>Sr<sup>2+</sup>) is a fission byproduct of uranium and plutonium production, and therefore understanding its environmental fate is of particular importance for predicting the evolution of long-term risk from historical releases. The nonradioactive strontium cation, Sr<sup>2+</sup>, is a chemical analog for <sup>90</sup>Sr<sup>2+</sup> that is often used in studies designed to understand the environmental behaviors of <sup>90</sup>Sr<sup>2+</sup>. The focus of this work was on understanding the dynamics of remobilization of strontium following evaporation to dryness in porous media. Evaporation is ubiquitous in the unsaturated zone, and has the potential to significantly impact the dynamics of transport by driving adsorption or precipitation on solid surfaces. For this work, a series of transport experiments were conducted examining the behavior of strontium over a range of pH values, ionic strengths, and concentrations. Saturated transport experiments were conducted, followed by experiments designed to examine the release and transport following evaporation to dryness. Results show increasing saturated retardation with increasing pH, decreasing ionic strength, and decreasing concentration, with the concentration exhibiting the strongest effect. Breakthrough curves at low concentrations were also found to be consistent with significant rate-limited desorption. Remobilization elution curves measured following evaporation to dryness exhibited the high initial effluent concentrations, exceeding the influent strontium concentration, most likely caused by the initial dissolution and accumulation of strontium by the advancing solution. Concentrations at later times were found to be largely consistent with the dynamics of saturated transport for the systems studied.https://www.mdpi.com/2073-4441/12/5/1461strontiumtransportunsaturated zoneevaporationrate-limited desorption |
| spellingShingle | William C. Weaver Tohren C. G. Kibbey Charalambos Papelis Dissolution-Desorption Dynamics of Strontium During Elution Following Evaporation: pH and Ionic Strength Effects Water strontium transport unsaturated zone evaporation rate-limited desorption |
| title | Dissolution-Desorption Dynamics of Strontium During Elution Following Evaporation: pH and Ionic Strength Effects |
| title_full | Dissolution-Desorption Dynamics of Strontium During Elution Following Evaporation: pH and Ionic Strength Effects |
| title_fullStr | Dissolution-Desorption Dynamics of Strontium During Elution Following Evaporation: pH and Ionic Strength Effects |
| title_full_unstemmed | Dissolution-Desorption Dynamics of Strontium During Elution Following Evaporation: pH and Ionic Strength Effects |
| title_short | Dissolution-Desorption Dynamics of Strontium During Elution Following Evaporation: pH and Ionic Strength Effects |
| title_sort | dissolution desorption dynamics of strontium during elution following evaporation ph and ionic strength effects |
| topic | strontium transport unsaturated zone evaporation rate-limited desorption |
| url | https://www.mdpi.com/2073-4441/12/5/1461 |
| work_keys_str_mv | AT williamcweaver dissolutiondesorptiondynamicsofstrontiumduringelutionfollowingevaporationphandionicstrengtheffects AT tohrencgkibbey dissolutiondesorptiondynamicsofstrontiumduringelutionfollowingevaporationphandionicstrengtheffects AT charalambospapelis dissolutiondesorptiondynamicsofstrontiumduringelutionfollowingevaporationphandionicstrengtheffects |