Comparative study of carbon nanotubes and granular activated carbon: Physicochemical properties and adsorption capacities

JOURNAL OF HAZARDOUS MATERIALS

卷:302

Article

Gangupomu, Roja Haritha¹  Sattler, Melanie L.¹  Ramirez, David² 

[1] Univ Texas Arlington, Dept Civil Engn, Arlington, TX 76019 USA

[2] Texas A&M Kingsville, Dept Environm Engn, Kingsville, TX 78363 USA

关键词: Adsorption;    Nanotubes;    Granular activated carbon;    Hazardous air pollutant;    Toluene;   

DOI  :  10.1016/j.jhazmat.2015.09.002

来源: Elsevier

【 摘 要 】

The overall goal was to determine an optimum pre-treatment condition for carbon nanotubes (CNTs) to facilitate air pollutant adsorption. Various combinations of heat and chemical pre-treatment were explored, and toluene was tested as an example hazardous air pollutant adsorbate. Specific objectives were (1) to characterize raw and pre-treated single-wall (SW) and multi-wall (MW) CNTs and compare their physical/chemical properties to commercially available granular activated carbon (GAC), (2) to determine the adsorption capacities for toluene onto pre-treated CNTs vs. GAC. CNTs were purified via heat-treatment at 400 degrees C in steam, followed by nitric acid treatment (3N, 5N, 11N, 16N) for 3-12 h to create openings to facilitate adsorption onto interior CNT sites. For SWNT, Raman spectroscopy showed that acid treatment removed impurities up to a point, but amorphous carbon reformed with 10 h-6N acid treatment. Surface area of SWNTs with 3 h-3N acid treatment (1347 m(2)/g) was higher than the raw sample (1136 m(2)/g), and their toluene maximum adsorption capacity was comparable to GAC. When bed effluent reached 10% of inlet concentration (breakthrough indicating time for bed cleaning), SWNTs had adsorbed 240 mg/g of toluene, compared to 150 mg/g for GAC. Physical/chemical analyses showed no substantial difference for pre-treated vs. raw MWNTs. (C) 2015 Elsevier B.V. All rights reserved.

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