Investigation of adsorption properties of Ce(III) ions from aqueous solutions by raw and modified olive pomace

The olive oil production waste, olive pomace is an environmentally friendly biosorbent because it consists of organic structure such as lignin, cellulose and hemi cellulose. In this study, olive pomace was aimed to investigate the availability of the removal of the cerium (III) ions from aqueous solutions. For this purpose, both raw and modified with phosphoric acid olive pomace samples and nanocomposite of modified olive pomace and nano magnetite particles were aimed to analyse the sorption conditions by batch method. For the characterization of the adsorbents, BET surface area, SEM and TEM images, FT-IR spectrometry, VSM analysis were used. In the adsorption studies, the parameters effect the adsorption efficiency were researched such as solution pH, contact time, initial Ce(III) concentration and temperature. According to the data taken from adsorption trials, the optimum conditions for raw olive pomace was determined as pH 3, 120 minutes contact time, 50 ppm Ce(III) concentration; for the modified olive pomace pH 4, 120 minutes contact time, 50 ppm Ce(III) concentration, and for the nanocomposite adsorbent pH 6, 45 minutes contact time, 100 ppm Ce(III) concentration. For all adsorbent, higher temperature decreases efficiency. For the determination of the adsorption model, Langmuir, Freundlich and Dubinin-Radushkebich isotherms were used and corresponding parameters are calculated. And also, adsorption thermodynamic parameters were calculated such as enthalpy, Gibbs free energy change, entropy.