Modeling studies for adsorption of phenol and co-pollutants onto granular activated carbon prepared from olive oil industrial waste

Abstract

Granular activated carbon (OSAC) which was derived from olive oil industrial solid waste was chemically activated with different concentrations of phosphoric acid. OSAC-materials were evaluated for their ability to remove phenol from aqueous solution in a batch technique. Adsorption isotherms were determined and modeled with five linear Langmuir forms, namely the Freundlich, Elovich, Temkin, Kiselev and Hill-de Boer models. The experimental data for the adsorption of phenol onto OSAM-materials were fitted well with the Langmuir-1 and 2, Freundlich, Kiselev and Hill-de Boer models. Adsorption was carried out on energetically different sites as localized monolayer adsorption and was an exothermic process. The uptake of phenol onto OSAC increased in the following order: OSAC-80%> OSAC-70%> OSAC-60%; the maximum adsorption capacities of phenol were found to be 114.416, 125.628 and 262.467 mg/g onto OSAC-60%, OSAC-70% and OSAC-80%, respectively. On the other hand, OSAC-80% was used as a good adsorbent for the removal of phenol and Cd²⁺ as co-pollutants from waste aqueous solutions. 80.25% of phenol and 50.66% of Cd²⁺ can be simultaneously removed by OSAC-80%.