Transport of copper as affected by titania nanoparticles in soil columns

The effects of TiO₂ nanoparticles on the transport of Cu through four different soil columns were studied. For two soils (HB and DX), TiO₂ nanoparticles acted as a Cu carrier and facilitated the transport of Cu. For a third soil (BJ) TiO₂ nanoparticles also facilitated Cu transport but to a much lesser degree, but for a fourth soil (HLJ) TiO₂ nanoparticles retarded the transport of Cu. Linear correlation analysis indicated that soil properties rather than sorption capacities for Cu primary governed whether TiO₂ nanoparticles-facilitated Cu transport. The TiO₂-associated Cu of outflow in the Cu-contaminated soil columns was significantly positively correlated with soil pH and negatively correlated with CEC and DOC. During passage through the soil columns 46.6-99.9% of Cu initially adsorbed onto TiO₂ could be “stripped” from nanoparticles depending on soil, where Cu desorption from TiO₂ nanoparticles increased with decreasing flow velocity and soil pH.