Stability of titania nanoparticles in soil suspensions and transport in saturated homogeneous soil columns.
The stability of TiO(2) nanoparticles in soil suspensions and their transport behavior through saturated homogeneous soil columns were studied. The results showed that TiO(2) could remain suspended in soil suspensions even after settling for 10 days. The suspended TiO(2) contents in soil suspensions after 24h were positively correlated with the dissolved organic carbon and clay content of the soils, but were negatively correlated with ionic strength, pH and zeta potential. In soils containing soil particles of relatively large diameters and lower solution ionic strengths, a significant portion of the TiO(2) (18.8-83.0%) readily passed through the soils columns, while TiO(2) was significantly retained by soils with higher clay contents and salinity. TiO(2) aggregate sizes in the column outflow significantly increased after passing through the soil columns. The estimated transport distances of TiO(2) in some soils ranged from 41.3 to 370 cm, indicating potential environmental risk of TiO(2) nanoparticles to deep soil layers.
Fang
Jing
J
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
Shan
Xiao-quan
XQ
Wen
Bei
B
Lin
Jin-ming
JM
Owens
Gary
G
D000538:Aluminum Silicates; D000077215:Clay; D054750:Ecotoxicology / Q000379:methods*; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D053758:Nanoparticles / Q000737:chemistry*; D012987:Soil; D012989:Soil Pollutants / Q000737:chemistry*; D013535:Suspensions; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*
D000538:Aluminum Silicates; D006812:Humic Substances; D012987:Soil; D012989:Soil Pollutants; D013535:Suspensions; C009495:titanium dioxide; D014025:Titanium; D000077215:Clay