Journal
WATER RESEARCH
Volume 43, Issue 17, Pages 4249-4257Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.watres.2009.06.005
Keywords
NOM; Nanoparticles; Calcium ions; Stability; Aggregation
Funding
- U.S. Environmental Protection Agency [RD831713, RD-83385601]
- Richard Snell Chair of Civil and Environmental Engineering
- Ira A. Fulton School of Engineering at Arizona State University
Ask authors/readers for more resources
The stability of nanoparticles in aquatic environment plays an important role in determining their environmental implication and potential risk to human health. This research studied the impact of natural organic matter (NOM) and divalent cations (Ca2+) on the stability of engineered metal oxide nanoparticles (e.g. ZnO, NiO, TiO2, Fe2O3 and SiO2). When nanoparticles were present in neutral water, a relatively weak electrolyte concentration (0.01 M KCl) could result in their aggregation; however, with the addition of 1 mg/L NOM, the negative surface charge of nanoparticles increased significantly and therefore their propensity to aggregate is reduced. 4 mg/L NOM stabilized most nanoparticles by producing -30 mV or higher zeta potentials. On the other hand, the negative charge that NOM imparted to nanoparticles could be neutralized by divalent cations (calcium ions). 0.04 M-0.06 M Ca2+ induced the aggregation of NOM-coated nanoparticles. It should be noted that among all the studied nanoparticles, SiO2 exhibited the unique stability due to its low NOM adsorption capacity and small Hamaker constant. SiO2 remained stable no matter whether the solution contained NOM or Ca2+. (C) 2009 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available