Transport of fullerene nanoparticles (nC60) in saturated sand and sandy soil: controlling factors and modeling.
Understanding subsurface transport of fullerene nanoparticles (nC(60)) is of critical importance for the benign use and risk management of C(60). We examined the effects of several important environmental factors on nC(60) transport in saturated porous media. Decreasing flow velocity from approximately 10 to 1 m/d had little effect on nC(60) transport in Ottawa sand (mainly pure quartz), but significantly inhibited the transport in Lula soil (a sandy, low-organic-matter soil). The difference was attributable to the smaller grain size, more irregular and rougher shape, and greater heterogeneity of Lula soil. Increasing ionic strength and switching background solution from NaCl to CaCl(2) enhanced the deposition of nC(60) in both sand and soil columns, but the effects were more significant for soil. This was likely because the clay minerals (and possibly soil organic matter) in soil responded to changes of ionic strength and species differently than quartz. Anions in the mobile phase had little effect on nC(60) transport, and fulvic acid in the mobile phase (5.0 mg/L) had a small effect in the presence of 0.5 mM Ca(2+). A two-site transport model that takes into account both the blocking-affected attachment process and straining effects can effectively model the breakthrough of nC(60).
College of Environmental Science and Engineering/Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Wei Jin Road 94, Tianjin 300071, China.
Lunliang
L
Zhang
Lei
L
Hou
Lilin
L
Wang
Amy T
AT
Kan
Wei
W
Chen
Mason B
MB
Tomson
D001578:Benzopyrans / Q000737:chemistry; D037741:Fullerenes / Q000737:chemistry*; D006812:Humic Substances / Q000032:analysis; D008956:Models, Chemical; D009038:Motion; D053758:Nanoparticles / Q000737:chemistry*; D009994:Osmolar Concentration; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000737:chemistry*
D001578:Benzopyrans; D037741:Fullerenes; D006812:Humic Substances; D012987:Soil; D012989:Soil Pollutants; D012822:Silicon Dioxide; C005023:fulvic acid