Environmental Earth Sciences

, Volume 71, Issue 8, pp 3751–3760

Transport and mobilization of multiwall carbon nanotubes in quartz sand under varying saturation

  • Abenezer Mekonen
  • Prabhakar Sharma
  • Fritjof Fagerlund
Original Article

DOI: 10.1007/s12665-013-2769-1

Cite this article as:
Mekonen, A., Sharma, P. & Fagerlund, F. Environ Earth Sci (2014) 71: 3751. doi:10.1007/s12665-013-2769-1

Abstract

In this study, a series of sand packed columns were used to investigate the mobility of multiwall carbon nanotubes (MWCNTs) in unsaturated porous media under unfavorable conditions for deposition. The flow through column experiments were designed to assess water content, flow rate, and grain size effect on the mobility of MWCNTs. It was found that variation in water content had no significant effect on retention of MWCNTs until it was lowered to 16 % effective saturation. Thick water films, high flow rate, and repulsive forces between MWCNTs and porous media made MWCNTs highly mobile. Different porous media grain sizes (D50 = 150–300 μm) were used in this study. The mobility of MWCNTs slightly decreased in finer grain sands, which was deemed to be an effect of increase in surface area and the number of depositional sites, in combination with low-pore water velocity. However, physical straining was not observed in selected fine-grain sands and aspect ratio of MWCNTs had low impact on mobility. Variations in pore-water velocity were produced by both changes in water saturation and in flow rate. At high pore-water velocities, the MWCNTs were generally mobile. However, for the combination of low-pore water velocity with either low water saturation or small grain size, some retention of MWCNTs was observed. Hence, low velocity in combination with flow through smaller pores increased MWCNT deposition.

Keywords

MWCNTs Mobility Unsaturated porous media Water content Flow rate 

Supplementary material

12665_2013_2769_MOESM1_ESM.pdf (344 kb)
Supplementary material 1 (PDF 344 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Abenezer Mekonen
    • 1
  • Prabhakar Sharma
    • 1
  • Fritjof Fagerlund
    • 1
  1. 1.Department of Earth SciencesUppsala UniversityUppsalaSweden