TY - JOUR
T1 - Cr(VI) Adsorption on Engineered Iron Oxide Nanoparticles
T2 - Exploring Complexation Processes and Water Chemistry
AU - Pan, Zezhen
AU - Zhu, Xiaoming
AU - Satpathy, Anshuman
AU - Li, Wenlu
AU - Fortner, John D.
AU - Giammar, Daniel E.
N1 - Publisher Copyright:
Copyright © 2019 American Chemical Society.
PY - 2019/10/15
Y1 - 2019/10/15
N2 - Surface-functionalized magnetic nanoparticles are promising adsorbents due to their large surface areas and ease of separation after contaminant removal. In this work, the affinity of Cr(VI) adsorption to 8 nm surface-functionalized superparamagnetic magnetite nanoparticles was determined for surface coatings with amine (trimethyloctadecylammonium bromide, CTAB) and carboxyl (stearic acid, SA) functional groups. Cr(VI) adsorbed more strongly to the CTAB-coated nanoparticles than to the SA-coated materials due to electrostatic interactions between positively charged CTAB and anionic Cr(VI) species. The adsorption of Cr(VI) by CTAB- A nd SA-coated nanoparticles increased with decreasing pH (4.5-10), which could be simulated by a surface complexation model. Cr(VI) removal performance by the nanocomposite was evaluated for two realistic drinking water compositions. The co-occurrence of divalent cations (Ca2+ and Mg2+) and Cr(VI) resulted in decreased Cr(VI) adsorption as particles were destabilized, leading to the aggregation and lower effective surface area, confirming the importance of the overall water composition on the performance of novel engineered nanomaterials for water treatment applications.
AB - Surface-functionalized magnetic nanoparticles are promising adsorbents due to their large surface areas and ease of separation after contaminant removal. In this work, the affinity of Cr(VI) adsorption to 8 nm surface-functionalized superparamagnetic magnetite nanoparticles was determined for surface coatings with amine (trimethyloctadecylammonium bromide, CTAB) and carboxyl (stearic acid, SA) functional groups. Cr(VI) adsorbed more strongly to the CTAB-coated nanoparticles than to the SA-coated materials due to electrostatic interactions between positively charged CTAB and anionic Cr(VI) species. The adsorption of Cr(VI) by CTAB- A nd SA-coated nanoparticles increased with decreasing pH (4.5-10), which could be simulated by a surface complexation model. Cr(VI) removal performance by the nanocomposite was evaluated for two realistic drinking water compositions. The co-occurrence of divalent cations (Ca2+ and Mg2+) and Cr(VI) resulted in decreased Cr(VI) adsorption as particles were destabilized, leading to the aggregation and lower effective surface area, confirming the importance of the overall water composition on the performance of novel engineered nanomaterials for water treatment applications.
UR - https://www.scopus.com/pages/publications/85073183131
U2 - 10.1021/acs.est.9b03796
DO - 10.1021/acs.est.9b03796
M3 - Article
C2 - 31556295
AN - SCOPUS:85073183131
SN - 0013-936X
VL - 53
SP - 11913
EP - 11921
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 20
ER -