Lead Adsorption and Desorption at the Barite (001) Surface in the Presence of EDTA
- Queens College, City University of New York, NY (United States); NYC Department of Health and Mental Hygiene, NY (United States)
- University of Chicago, IL (United States); Argonne National Laboratory (ANL), Argonne, IL (United States)
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- University of Chicago, IL (United States)
- Queens College, City University of New York, NY (United States); University of New Mexico, Albuquerque, NM (United States)
- Queens College, City University of New York, NY (United States)
Scaling minerals, such as barite, can cause detrimental consequences for oil/gas pipelines and water systems, but their formation can be inhibited by organic chelators such as ethylenediaminetetraacetic acid (EDTA). Here, we resolve how EDTA affects sorption and desorption of Pb at the barite (001) surface using a combination of X-ray scattering and microscopy measurements. In the presence of EDTA, Pb incorporated in the topmost part of the barite surface and adsorbed as inner-sphere complexes on the surface. In barite saturated solutions containing [Pb] ≥ 100 μM, overgrowth films grew along step edges. These films were exclusively monolayer thick, indicating that their growth was a self-limiting process. Approximately half of the Pb was removed after 14.5 h reaction with a Pb-free EDTA solution where most of the desorption occurred to adsorbed Pb rather than incorporated Pb. Dissolution proceeded primarily via step retreat and etch pit formation in EDTA, but in deionized water, the secondary phase was quickly removed within 3 min. Together these results suggest EDTA binds to both the surface and Pb in solution, which limits Pb sorption. However, EDTA binding to the surface also inhibits removal of the secondary phase that formed at higher Pb concentrations.
- Research Organization:
- Queens College, City University of New York, NY (United States)
- Sponsoring Organization:
- National Science Foundation-Earth Sciences; USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division (CSGB); USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division (CSGB); USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF)
- Grant/Contract Number:
- AC02-06CH11357; SC0024588
- OSTI ID:
- 2499447
- Alternate ID(s):
- OSTI ID: 2499448
- Journal Information:
- ACS ES&T Water, Journal Name: ACS ES&T Water Journal Issue: 1 Vol. 5; ISSN 2690-0637
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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OSTI ID:1776716