Adsorptive removal of some carbonyl containing compounds from aqueous solutions using Iraqi porcelanite rocks: a kinetic-model study

Abstract

The kinetics of removal of Acetaldehyde (A,Al), Benzaldehyde (B.al),2-Butanone (2-But), Acetophenone (A.Ph) and Benzophenone (B.Ph) from their aqueous solution by adsorption onto powder of Iraqi Porcelanite rocks was investigated. The results were treated by non-linear pseudo-first order (PFO) and non-linear pseudo-second order (PSO) models, the latter model was better fitting with experimental data. Furthermore, the non-linear treatment indicates that the time periods of the operation is longer than that estimated from direct observation, hence the quantity of adsorption at equilibrium will be greater than observed directly. Another advantage of non-linear treatment not mentioned before is deducing kinetic model best fitting with data by expecting the equilibrium time of the process depending on the data pointsof initial time period. The obtained kinetic parameters were correlated with some molar parameters using multi-variable linear regression which show that molar polarizability has a promotional effect upon kinetic adsorption parameters, while molar volume and hydrophobicity have a demotion effect. The kinetic investigation was extended to include diffusion Boyd’, and Weber-Morris models. The results showed that A.Al and 2-But had a film diffusion kinetic determining step, the remaining compounds show a non-diffusional (local adhering) like behavior.

Keywords

• kinetics
• adsorption
• carbonyl compounds
• porcelanite