Title: | The role of beaded activated carbon's surface oxygen groups on irreversible adsorption of organic vapors |
Author(s): | Jahandar Lashaki M; Atkinson JD; Hashisho Z; Phillips JH; Anderson JE; Nichols M; |
Address: | "University of Alberta, Department of Civil and Environmental Engineering, Edmonton, AB T6 G 2W2, Canada. University of Alberta, Department of Civil and Environmental Engineering, Edmonton, AB T6 G 2W2, Canada. Electronic address: hashisho@ualberta.ca. Ford Motor Company, Environmental Quality Office, Dearborn, MI 48126 USA. Ford Motor Company, Research and Advanced Engineering, Dearborn, MI 48121 USA" |
DOI: | 10.1016/j.jhazmat.2016.05.087 |
ISSN/ISBN: | 1873-3336 (Electronic) 0304-3894 (Linking) |
Abstract: | "The objective of this study is to determine the contribution of surface oxygen groups to irreversible adsorption (aka heel formation) during cyclic adsorption/regeneration of organic vapors commonly found in industrial systems, including vehicle-painting operations. For this purpose, three chemically modified activated carbon samples, including two oxygen-deficient (hydrogen-treated and heat-treated) and one oxygen-rich sample (nitric acid-treated) were prepared. The samples were tested for 5 adsorption/regeneration cycles using a mixture of nine organic compounds. For the different samples, mass balance cumulative heel was 14 and 20% higher for oxygen functionalized and hydrogen-treated samples, respectively, relative to heat-treated sample. Thermal analysis results showed heel formation due to physisorption for the oxygen-deficient samples, and weakened physisorption combined with chemisorption for the oxygen-rich sample. Chemisorption was attributed to consumption of surface oxygen groups by adsorbed species, resulting in formation of high boiling point oxidation byproducts or bonding between the adsorbates and the surface groups. Pore size distributions indicated that different pore sizes contributed to heel formation - narrow micropores (<7A) in the oxygen-deficient samples and midsize micropores (7-12A) in the oxygen-rich sample. The results from this study help explain the heel formation mechanism and how it relates to chemically tailored adsorbent materials" |
Keywords: | Activated carbon Cyclic adsorption/regeneration Irreversible adsorption Surface oxygen group Volatile organic compound; |
Notes: | "PubMed-not-MEDLINEJahandar Lashaki, Masoud Atkinson, John D Hashisho, Zaher Phillips, John H Anderson, James E Nichols, Mark eng Netherlands 2016/06/14 J Hazard Mater. 2016 Nov 5; 317:284-294. doi: 10.1016/j.jhazmat.2016.05.087. Epub 2016 May 31" |