Multitechnique
Investigation of the pH Dependence
of Phosphate Induced Transformations of ZnO Nanoparticles
Sewwandi Rathnayake
Jason M. Unrine
Jonathan Judy
Anne-Frances Miller
William Rao
Paul M. Bertsch
10.1021/es404544w.s001
https://acs.figshare.com/articles/journal_contribution/Multitechnique_Investigation_of_the_pH_Dependence_of_Phosphate_Induced_Transformations_of_ZnO_Nanoparticles/2299984
In order to properly evaluate the
ecological and human health risks
of ZnO manufactured nanomaterials (MNMs) released to the environment,
it is critical to understand the likely transformation products in
various environments, such as soils, surface and ground waters, and
wastewater treatment processes. To address this knowledge gap, we
examined the transformation of 30 nm ZnO MNMs in the presence of different
concentrations of phosphate as a function of time and pH using a variety
of orthogonal analytical techniques. The data reveal that ZnO MNMs
react with phosphate at various concentrations and transform into
two distinct morphological/structural phases: a micrometer scale crystalline
zinc phosphate phase (hopeite-like) and a nanoscale phase that likely
consists of a ZnO core with an amorphous Zn<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub> shell. The P species composition was also pH dependent,
with 82% occurring as hopeite-like P at pH 6 while only 15% occurred
as hopeite-like P at pH 8. These results highlight how reactions of
ZnO MNMs with phosphate are influenced by environmental variables,
including pH, and may ultimately result in structurally and morphologically
heterogeneous end products.
2014-05-06 00:00:00
wastewater treatment processes
zinc phosphate phase
ZnO MNMs
pH
Phosphate Induced Transformations
P species composition
ZnO NanoparticlesIn order
30 nm ZnO MNMs