Effect of humic acid on the transport of vanadium oxides nanoparticles in water saturated packed columns.

Abundant vanadium oxides nanoparticles (VOx NPs) release to environment during their production and application. However, little is known on their environmental behaviors, especially under the influence of ubiquitous organic matter (OM). This study investigated the transport of V2O5, VO2, and V2O3 NPs in saturated aquifer in the presence of humic acid (HA), the main dissolved OM in aqueous environment. HA at lower concentration (0.1 mg C/L) blocked the migration of VOx NPs, especially for VO2 NPs. With the increase of HA concentration to 0.5 mg C/L and 1 mg C/L, the mobility of VOx NPs increased. VOx-NPs migration also accelerated in actual aquifer medium with the addition of HA at 0.5 mg C/L. The experimental results were verified by XDLVO calculation of particle-particle and particle-medium energy barrier changes. The relative contributions of advection, dispersion, binding force, gravity, were quantified by MMS equation. The rate coefficient of VOx NPs transport in quartz sand was determined by the two-point dynamic attachment model of HYDRUS-1D. The particle trajectory model revealed the migration path of VOx NPs. These findings contribute to a comprehensive understanding of the migration of VOx NPs in environment, which is helpful to develop strategies for their risks management.