Mobilization of Multi-walled Carbon Nanotubes in Partially Saturated Porous Media
2011 (English)Conference paper (Other (popular science, discussion, etc.))
Carbon nanotubes (CNTs) are important engineered nanoparticles with unique and beneficial properties. As aresult CNTs has been used in a wide range of commercial products including electronics, optical devices and drugdelivery leading to their disposal in the natural environment. Literature studies have investigated the mobility ofCNTs in saturated porous media under differing physical and chemical conditions. However CNT transport inunsaturated porous media has not been investigated thus far. This study investigated the transport of Multi WalledCNTs (MWCNTs) at different water contents and flow rates, a common situation in the event of infiltration/rainfallin the upper layer of the unsaturated subsurface.We have used a column packed with silica sand, at different watercontents by applying a suction at the base of the column, and sprinkled the MWCNTs solution at different flowrates at the top of the column. Experiments suggest that MWCNTs deposition was independent of the changein water content (until 21% of total pore space) of the porous media for chosen applied suction if the flow ratesare higher ( 0.5 m/day). There was a significant amount of MWCNTs filtration occurred at low flow rates (0.1m/day) and no filtration occurred at high flow rates (4 m/day) at any porous media saturation. In transient flowconditions, all the deposited nanotubes at low flow rates were re-mobilized after application of high flow rates. Allthese findings indicated that the nanotubes were possibly deposited in the immobile zone created in the relativelysmaller pores during low flow conditions and straining did not significantly affect the nanotubes filtration.
Place, publisher, year, edition, pages
Nanoparticle, transport, column experiment, soil
Research subject Earth Science with specialization in Environmental Analysis
IdentifiersURN: urn:nbn:se:uu:diva-152181OAI: oai:DiVA.org:uu-152181DiVA: diva2:412813
European Geosciences Union, General Assembly, Vienna, Austria, 03–08 April 2011