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Mobility of Acid‐Treated Carbon Nanotubes in Water‐Saturated Porous Media
Author(s) -
Peng X. J.,
Du C. J.,
Liang Z.,
Wang J.,
Luan Z. K.,
Li W. J.
Publication year - 2011
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2010.0311
Subject(s) - carbon nanotube , zeta potential , nanomaterials , ionic strength , chemical engineering , nitric acid , chemistry , humic acid , ionic bonding , porous medium , materials science , nuclear chemistry , inorganic chemistry , porosity , nanotechnology , nanoparticle , organic chemistry , ion , aqueous solution , fertilizer , engineering
The production, use, and disposal of nanomaterials may inevitably lead to their appearance in water. With the development of new industries around nanomaterials, it seems necessary to be concerned about the transport of nanomaterials in the environment. In this paper, the transport of acid‐treated carbon nanotubes (CNTs) in porous media was investigated. Before the mobility investigation, the stability of acid‐treated CNT dispersions was studied using ultraviolet‐visible spectra and it was indicated that, under the chemical conditions employed in this work, there was no apparent aggregation. The mobility investigation showed that transport of acid‐treated CNTs increased with treatment time due to increase in particle zeta potential. Carbon nanotubes treated with nitric acid for 2, 6, and 12 h possessed measured zeta potentials of −30.0, −43.0, and −48.5 mV, respectively. Utilizing clean‐bed filtration theory, we showed that acid‐treated CNTs have the potential to migrate 3.28, 5.67, and 7.69 m in saturated glass beads, respectively. We showed that solution ionic strength and pH have important effects on the mobility of acid‐treated CNTs. Increasing the pH from 6.0 to 7.9 resulted in an increase in migration potential from 2.96 to 10.86 m. Increasing the ionic strength from 0.005 to 0.020 M resulted in a decrease in CNT migration potential from 5.67 to 1.42 m.