Equilibrium isotherms and dynamics of sorption of metal ions by olive cake

Abstract EN

The capability of raw olive cake for removing metal ions from aqueous solutions has been determined by shake-flask experiments at system operating conditions for sorbent (particle size and concentration) and for solution (initial metal ion concentration, initial pH and temperature).

The maximum sorption capacity obtained was 99 and 34 mg/g sized 90-180 jum for Pb and Ni ions, respectively.

In general, the sorption capacity decreased with increase in particle size and sorbent concentration while it increased with increase in initial metal ion concentration and initial solution pH.

Effect of solution temperature was little for both cations.

Sorption of Pb ions followed Langmuir adsorption isotherm while Fruendlich model was found suitable for Ni ions.

Redlich-Peterson model can be used for either metal.

The proposed mechanism is physical adsorption but ion exchange is expected to play a limited role.

Both external mass transfer and intraparticle diffusion were important as rate-controlling steps.