Adsorption Characteristics of Benzaldehyde, Sulphanilic acid, and p‐Phenolsulfonate from Water, Acid, or Base Solutions onto Activated Carbon Cloth

Abstract

Adsorption of benzaldehyde (BA), sulphanilic acid (SA), and sodium salt of p‐phenolsulfonic acid (p‐PhS) from water, acid, or base solutions onto activated carbon cloth (ACC) was studied by in‐situ UV‐spectrophotometric method. Kinetics of adsorption was followed over 90 min and the data were fitted to first order rate law. The order of rate of adsorption was found to be BA>SA≈p‐PhS in water, BA>p‐PhS>SA in 1 M H₂SO₄ and BA>SA >> p‐PhS in 0.1 M NaOH. Competitive adsorptions of BA and SA from an equimolar mixture in 1 M H₂SO₄ and of BA and p‐PhS from an equimolar mixture in H₂O were studied for exploring the possibilities of separation of binary mixtures. It was found that p‐PhS was not adsorbed at all from 0.1 M NaOH solution. Adsorption isotherms of BA, SA, and p‐PhS at 30°C were derived and the data were fitted to the Langmuir and Freundlich models. The Freundlich model was found to represent the experimental data better than the Langmuir model.

Keywords:

• Adsorption
• competitive adsorption
• activated carbon cloth
• benzaldehyde
• sulphanilic acid
• p‐phenolsulfonate

Acknowledgements

The authors would like to thank the Scientific Research Projects Unit of Akdeniz University for support of this work through project 2003.01.0300.009 and to the central laboratory of METU (Middle East Technical University) for determining the surface properties of ACC.