Adsorption of lead(II) from aqueous solution onto several types of activated carbon fibers.

Leyva-Ramos*, M.S. Berber-Mendoza, J. Salazar-Rabago, R.M. Guerrero-Coronado, and J. Mendoza-Barron,
Adsorption, 17:515-526., 2011.


In this work, the adsorption of Pb(II) from aque- ous solution was investigated on various types of activated carbon fibers (ACFs) manufactured from polyacrylonitrile and phenolic resin. The textural and physicochemical prop- erties of the ACFs were determined by the N2 -BET method and acid-base titration. The experimental adsorption equi- librium data of Pb(II) on the ACFs were obtained in a batch adsorber, and the Langmuir isotherm model better fitted the experimental data. The effects of the type of ACF and pre- cursor of ACF, solution pH and temperature upon the ad- sorption of Pb(II) on the ACFs were examined in detail. The adsorption capacity was highly dependent upon the pre- cursor of ACF. The Pb(II) adsorption capacity of the ACFs augmented when the solution pH and temperature were in- creased from 2 to 4 and from 288 to 308 K, respectively. The effect of the pH was attributed to the interactions be- tween the surface of the ACF and Pb2+ ions present in the water solution. The Pb(II) adsorption capacity of the ACFs was enhanced by oxidation with HNO3 solution and the en- hancement factor was between 1.1 and 1.4. The reversibility of the adsorption of Pb(II) was investigated by first adsorb- ing Pb(II) on an ACF and then desorbing the Pb(II). It was noticed that Pb(II) was substantially desorbed from ACF while reducing the solution pH to 2. It was concluded that the Pb(II) was mainly adsorbed on the ACFs by chemisorp- tion, electrostatic interactions and ion exchange.