Title: | Surface modification of coconut shell based activated carbon for the improvement of hydrophobic VOC removal |
Address: | "Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China" |
DOI: | 10.1016/j.jhazmat.2011.05.069 |
ISSN/ISBN: | 1873-3336 (Electronic) 0304-3894 (Linking) |
Abstract: | "In this study, coconut shell based carbons were chemically treated by ammonia, sodium hydroxide, nitric acid, sulphuric acid, and phosphoric acid to determine suitable modification for improving adsorption ability of hydrophobic volatile organic compounds (VOCs) on granular activated carbons (GAC). The saturated adsorption capacities of o-xylene, a hydrophobic volatile organic compound, were measured and adsorption effects of the original and modified activated carbons were compared. Results showed that GAC modified by alkalis had better o-xylene adsorption capacity. Uptake amount was enhanced by 26.5% and reduced by 21.6% after modification by NH(3)H(2)O and H(2)SO(4), respectively. Compared with the original, GAC modified by acid had less adsorption capacity. Both SEM/EDAX and BET were used to identify the structural characteristics of the tested GAC, while IR spectroscopy and Boehm's titration were applied to analysis the surface functional groups. Relationships between physicochemical characteristics of GAC and their adsorption performances demonstrated that o-xylene adsorption capacity was related to surface area, pore volume, and functional groups of the GAC surface. Removing surface oxygen groups, which constitute the source of surface acidity, and reducing hydrophilic carbon surface favors adsorption capacity of hydrophobic VOCs on carbons. The performances of modified GACs were also investigated in the purification of gases containing complex components (o-xylene and steam) in the stream" |
Keywords: | "Carbon/*chemistry Cocos/*chemistry Microscopy, Electron, Scanning Spectroscopy, Fourier Transform Infrared Surface Properties Volatile Organic Compounds/*isolation & purification;" |
Notes: | "MedlineLi, Lin Liu, Suqin Liu, Junxin eng Research Support, Non-U.S. Gov't Netherlands 2011/06/21 J Hazard Mater. 2011 Aug 30; 192(2):683-90. doi: 10.1016/j.jhazmat.2011.05.069. Epub 2011 May 27" |