Impact of surface characteristics of activated carbon on adsorption of BTEX

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2003-03, Vol.214 (1), p.181-193
• Main Authors: Daifullah, A.A.M, Girgis, B.S
• Format: Article
• Language: English
• Subjects: Activated carbon; Adsorption; Agricultural by-products; BTEX; Surface characteristics
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/S0927-7757(02)00392-8

Five residues of botanical origin were tested as potential activated carbon precursors; these are: date pits (DP), cotton stalks (CS), peach stones (PS), almond shells (ALS), and olive stones (OS). A standard activation procedure was followed (impregnation with 50% H 3PO 4 and heat treatment at 773 K) for the sake of comparison. Texture characteristics were determined by analysis of the N 2/77 K isotherms. Highly to good adsorbing carbons were obtained in the order: PS, ALS, CS, OS and DP, respectively. Acidity/basicity characteristics were estimated by the selective titration method of Boehm. All carbons contained residual phosphates and showed high content of surface oxygen complexes mostly of acidic type. Removal of benzene, toluene, ethylbenzene and p-xylene (BTEX) was evaluated for each component in the mixture and in terms of total uptake. Low amounts of BTEX were adsorbed, which were irregularly correlated to either of the porosity or surface–chemical parameters. It is assumed that the complexity of the carbon surface with developed porosity and high content of hydrophilic oxygen functionalities determine the uptake of the hydrophobic organic molecules. In general, the order of uptake appears consistent to previous investigations as B