Transport of TiO₂ nanoparticles and their effects on the mobility of Cu in soil media

The transport behavior of TiO₂ nanoparticles (TNPs) through different soil columns as well as their effects on the mobility of Cu was systematically examined. Results showed that a constant concentration plateau (C_f/C_o%) was achieved at experimental breakthrough curves, ranging from 89%, 53%, and 60% for soils Gölbaşı (Gö), Hacettepe (Ha), and Batikent (Ba) respectively. While Brownian diffusion was the predominant mechanism for TNPs removal in all three soils media, gravitational sedimentation also played a significant role, accounting for 10.58%, 35.52% and 28.84% of the overall single-collector contact efficiency for the soils Gö, Ha and Ba respectively. The estimated travel distances of TNPs in soils ranged from 100 to 593 cm, indicating potential risks of TNPs to the environment and public health. Desorption of Cu from TNPs ranging from 87.57 to 99.08%, demonstrates that TiO₂ nanoparticles-associated Cu may not be stable when released to soil media.