Deposition and transport of functionalized carbon nanotubes in water-saturated sand columns

JOURNAL OF HAZARDOUS MATERIALS

卷:213

Article

Tian, Yuan¹  Gao, Bin¹  Wang, Yu¹  Morales, Veronica L.²  Carpena, Rafael Munoz¹  Huang, Qingguo³  Yang, Liuyan⁴ 

[1] Univ Florida, Dept Agr & Biol Engn, Gainesville, FL 32611 USA

[2] Univ Abertay, SIMBIOS Ctr, Dundee DD1, Scotland

[3] Univ Georgia, Dept Crop & Soil Sci, Griffin, GA 30223 USA

[4] Nanjing Univ, Sch Environm, State Key Lab Pollut Control & Resource Reuse, Nanjing 210093, Jiangsu, Peoples R China

关键词: Transport;    Mobilization;    Surface charge heterogeneity;    SWNT;    MWNT;   

DOI  :  10.1016/j.jhazmat.2012.01.088

来源: Elsevier

【 摘 要 】

Knowledge of the fate and transport of functionalized carbon nanotubes (CNTs) in porous media is crucial to understand their environmental impacts. In this study, laboratory column and modeling experiments were conducted to mechanistically compare the retention and transport of two types of functionalized CNTs (i.e., single-walled nanotubes and multi-walled nanotubes) in acid-cleaned, baked, and natural sand under unfavorable conditions. The CNTs were highly mobile in the acid-cleaned sand columns but showed little transport in the both natural and baked sand columns. In addition, the retention of the CNTs in the both baked and natural sand was strong and almost irreversible even after reverse, high-velocity, or surfactant flow flushing. Both experimental and modeling results showed that pH is one of the factors dominatingCNT retention and transport in natural and baked sand. Retention of the functionalized CNTs in the natural and baked sand columns reduced dramatically when the system pH increased. Our results suggest that the retention and transport of the functionalized CNTs in natural sand porous media were mainly controlled by strong surface deposition through the electrostatic and/or hydrogen-bonding attractions between surface function groups of the CNTs and metal oxyhydroxide impurities on the sand surfaces. (C) 2012 Elsevier B.V. All rights reserved.

【 授权许可】

Free