Abstract Details
(2020) Rare Earth Elements as Process Indicators for Metal and Metaloid Contaminated Groundwater
Dean J, Srivastava P, Mitchell A & Perkins W
https://doi.org/10.46427/gold2020.534
The author has not provided any additional details.
13e: Room 4, Thursday 25th June 08:36 - 08:39
Joe Dean
Pallavee Srivastava
Andrew Mitchell
William Perkins View all 2 abstracts at Goldschmidt2020 View abstracts at 2 conferences in series
Pallavee Srivastava
Andrew Mitchell
William Perkins View all 2 abstracts at Goldschmidt2020 View abstracts at 2 conferences in series
Listed below are questions that have been submitted by the community that the author will try and cover in their presentation. To submit a question, ensure you are signed in to the website. Authors or session conveners approve questions before they are displayed here.
Submitted by Kip Solomon on Tuesday 23rd June 00:17
Thank you for your presentation. What are the transit times associated with your reverse particle tracking? I'm wondering about kinetic processes in this system. Thank you.
Hi Kip, thank you for the question. The modelled transit time was approximately 110-130 days from the borehole 47 to a constant head boundary at the site perimeter.
Thank you for your presentation. What are the transit times associated with your reverse particle tracking? I'm wondering about kinetic processes in this system. Thank you.
Hi Kip, thank you for the question. The modelled transit time was approximately 110-130 days from the borehole 47 to a constant head boundary at the site perimeter.
Submitted by Neil Sturchio on Tuesday 23rd June 16:21
Have you evaluated the role of pH in controlling the observed distribution of REE patterns?
Thank you for your question Neil. The surface water is in contact with a limestone outcrop 20 km north of the site, and as such has a relatively high pH(7-8) and alkalinity. I predict that these factors control the light-REE depleted surface water-type pattern. This is a common observation for surface water, and attributed to the fact the HREE form more stable aqueous complexes with bicarbonate etc preventing them from adsorbing on iron oxides. The pH of water in the aquifer is variable (pH 4.3-6.8), and likely associated with sources of contaminants. pH correlated reasonably well with total-REE (r=0.45), which is likely due to the protonation of mineral surfaces at lower pH, increasing mobility. I did not observe a correlation between pH and middle-REE enrichment nor between pH and LREE-enrichment. I have interpreted this as that although pH plays a role in controlling the absolute concentration of REE in groundwater, it does not necessarily control the magnitude of the observed enrichment's (in groundwater).
Have you evaluated the role of pH in controlling the observed distribution of REE patterns?
Thank you for your question Neil. The surface water is in contact with a limestone outcrop 20 km north of the site, and as such has a relatively high pH(7-8) and alkalinity. I predict that these factors control the light-REE depleted surface water-type pattern. This is a common observation for surface water, and attributed to the fact the HREE form more stable aqueous complexes with bicarbonate etc preventing them from adsorbing on iron oxides. The pH of water in the aquifer is variable (pH 4.3-6.8), and likely associated with sources of contaminants. pH correlated reasonably well with total-REE (r=0.45), which is likely due to the protonation of mineral surfaces at lower pH, increasing mobility. I did not observe a correlation between pH and middle-REE enrichment nor between pH and LREE-enrichment. I have interpreted this as that although pH plays a role in controlling the absolute concentration of REE in groundwater, it does not necessarily control the magnitude of the observed enrichment's (in groundwater).
Sign in to ask a question.