Heterogeneous Lead Phosphate Nucleation at Organic–Water Interfaces: Implications for Lead Immobilization
- Univ. of Houston, TX (United States). Dept. of Civil & Environmental Engineering
- Washington Univ., St. Louis, MO (United States). Dept. of Energy, Environmental and Chemical Engineering
- Washington Univ., St. Louis, MO (United States). Dept. of Earth and Planetary Sciences
- Argonne National Lab. (ANL), Argonne, IL (United States). X-ray Science Division
Phosphate is added to Pb-contaminated soils to induce lead immobilization through lead phosphate precipitation. Organic coatings on soils, which may affect heterogeneous lead phosphate nucleation, can impact the effectiveness of lead immobilization. SiO2 surfaces were coated with silanol self-assembled thin films terminated with -COOH and -OH functional groups to act as model organic coatings on soil particles. Using grazing incidence small-angle X-ray scattering (GISAXS), heterogeneous lead phosphate nucleation on coatings was measured from mixed Pb(NO3)2 and Na2HPO4/NaH2PO4 solutions at pH 7 with varied ionic strengths (IS = 0.58, 4, and 11 mM). Raman spectroscopy identified the homogeneous precipitates in solution as hydroxylpyromorphite (Pb5(PO4)3OH). The smallest lead phosphate nuclei (4.5 ± 0.5 nm) were observed on -COOH coatings, which resulted from the highest level of lead and phosphate ion adsorption on -COOH coatings. The IS of the solution also affected the sizes of the heterogeneous precipitates on -COOH coating, with smaller nuclei (1.3 ± 0.4 nm) forming under higher IS (4 and 11 mM). Finally, this study provided new findings that can improve our understanding of lead immobilization in contaminated soil environments.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of Houston, TX (United States); Washington Univ., St. Louis, MO (United States)
- Sponsoring Organization:
- National Science Foundation (NSF) (United States); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
- Grant/Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1484682
- Journal Information:
- ACS Earth and Space Chemistry, Journal Name: ACS Earth and Space Chemistry Journal Issue: 9 Vol. 2; ISSN 2472-3452
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Preventing the colloidal dispersion of Pb( iv ) corrosion scales and lead release in drinking water distribution systems
|
journal | January 2019 |
Advanced chemical stability diagrams to predict the formation of complex zinc compounds in a chloride environment
|
journal | January 2019 |
Organic–mineral interfacial chemistry drives heterogeneous nucleation of Sr-rich (Ba x , Sr 1− x )SO 4 from undersaturated solution
|
journal | May 2019 |
Similar Records
Chemistry of lead and cadmium in soil: solid phase formation
ON PRECIPITATION EFFECTS OF ALUMINUM, LANTHANUM, IRON(III), AND THORIUM PHOSPHATES