This study investigated the potential use of olive pomace (OP) as an adsorbent to
reduce the concentration of methyl orange (MO) in aqueous solutions. The effect of
some important parameters on the process of adsorption was examined, including
pH, adsorbent weight, temperature, contact time, agitation speed, and the initial
concentration of MO. The results showed that the optimum concentration of MO was
10 ppm and the optimum pH = 2, indicating that the process of MO adsorption on the
surface of the OP was better in acidic medium. The equilibrium time was 80 min at a
speed of 100 rpm. The results of the study showed the significant role of OP weight,
agitation speed, temperature and the contact time in increasing the adsorption
efficiency. On comparing the pseudo first order and pseudo second order models, the
results showed that the pseudo second order model fitted the experimental data well.
The study also included testing of Langmuir and Freundlich models on the
adsorption isotherm data, and it was found that experimental data obey the
Freundlich isotherm. To sum up, the study showed that OP has high adsorption
efficiency to remove MO by applying a simple, inexpensive method.