Jump to main content
Jump to site search

Issue 6, 2016
Previous Article Next Article

Trihalomethane, dihaloacetonitrile, and total N-nitrosamine precursor adsorption by carbon nanotubes: the importance of surface oxides and pore volume

Author affiliations

Abstract

As drinking water sources become increasingly impaired, enhanced removal of natural organic matter (NOM) may be required to curb formation of disinfection byproducts (DBPs) upon chlor(am)ination. While carbon nanotubes (CNTs) can adsorb NOM, their properties for DBP precursor adsorption have not been elucidated. Nine types of CNTs were assessed for trihalomethane (THM), dihaloacetonitrile (DHAN), and total N-nitrosamine (TONO) precursor adsorption. Batch isotherm experiments were completed with lake water and, to simulate an impaired condition, effluent from a wastewater treatment plant (WWTP). Adsorption varied with CNT type and dose, with TONO precursors having the highest percent removals from WWTP effluent (up to 97%). Physicochemical properties of CNTs were characterized by gas adsorption isotherms and X-ray photoelectron spectroscopy and numerical models were developed to identify CNT properties driving DBP precursor adsorption. The models fits were strong (R2 > 0.92) and indicated removal of the three precursor types increased with percent carboxyl groups (p < 0.01) and, for TONO precursors only, cumulative pore volume (CPV, p = 0.001). A multicollinearity analysis suggested surface oxides – particularly carboxyl groups – on the CNTs increased CPV, presumably by increasing electrostatic repulsive forces, which enhanced microporosity sufficiently to overshadow any repulsion of DBP precursors from negatively charged surface oxides. A size exclusion analysis revealed all CNT pores were accessible to TONO precursors, while THM and DHAN precursors had limited access to the smaller micropores. These findings provide a framework to modify CNTs to optimize adsorption of DBP precursors and demonstrate the potential of CNTs for TONO precursor removal.

Graphical abstract: Trihalomethane, dihaloacetonitrile, and total N-nitrosamine precursor adsorption by carbon nanotubes: the importance of surface oxides and pore volume

Back to tab navigation

Supplementary files

Publication details

The article was received on 28 Jul 2016, accepted on 27 Sep 2016 and first published on 28 Sep 2016


Article type: Paper
DOI: 10.1039/C6EW00193A
Citation: Environ. Sci.: Water Res. Technol., 2016,2, 1004-1013
  • Open access: Creative Commons BY-NC license
  •   Request permissions

    Trihalomethane, dihaloacetonitrile, and total N-nitrosamine precursor adsorption by carbon nanotubes: the importance of surface oxides and pore volume

    E. M. Needham, S. M. Sidney, J. R. Chimka and J. L. Fairey, Environ. Sci.: Water Res. Technol., 2016, 2, 1004
    DOI: 10.1039/C6EW00193A

    This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material and it is not used for commercial purposes.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements