Open AccessActive Carbon as an Adsorbent for Lead Ions
Author(s) -
Sohail Akhtar,
Riaz Qadeer
Publication year - 1997
Publication title -
adsorption science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.682
H-Index - 36
eISSN - 2048-4038
pISSN - 0263-6174
DOI - 10.1177/026361749701501007
Subject(s) - adsorption , chemistry , freundlich equation , ion , aqueous solution , diffusion , carbon fibers , reaction rate constant , langmuir , inorganic chemistry , active carbon , kinetics , activated carbon , analytical chemistry (journal) , chromatography , thermodynamics , organic chemistry , materials science , quantum mechanics , composite number , composite material , physics , environmental protection , environmental science
A commercial active carbon has been tested as an adsorbent for the removal of lead ions from aqueous solutions. Optimum conditions for maximum adsorption in terms of shaking time, lead ion concentration, temperature and concentration of different acids were established. The results obtained reveal that the adsorption of lead ions on active carbon is athermic (ΔH = 0) in nature and follows first-order kinetics. The first-order rate constant was evaluated as 0.049 min −1 and the intraparticle diffusion rate as 3.07 × 10 −4 (g/g min 1/2 ). The data also obey the Freundlich, Langmuir and Dubinin-Radushkevich (D-R) isotherm equations over the concentration range studied. The magnitude of the adsorption energy, 7.61 kJ/mol, calculated from the β-constant of the D-R equation lies in the energy range for physical adsorption which is attributed to weak bonding between the lead ions and the active carbon.