An interesting environmental friendly cleanup: The excellent potential of olive pomace for disperse blue adsorption/desorption from wastewater

The removal of Disperse Blue 73 from aqueous solutions, using olive pomace as adsorbent material, was investigated in a batch system with respect to contact time, pomace dosage, pH and temperature. SEM, FTIR-ATR, TG and XPS analyses appeared as powerful tools to characterize olive pomace, before and after the adsorption of dye, while UV–Visible analyses were used to quantify the amount of loaded dye on adsorbent material. The pseudo-second order kinetic model well fitted the experimental data and described the kinetic adsorption process. The dye desorption in glacial acetic acid was also obtained with the dye recovery enabling the recycle both of adsorbent material and dye itself. Five consecutive cycles of adsorption and desorption were performed and the absence of any degradation process affecting the dye after the adsorption/desorption cycles was observed. The recorded absorption spectrum, in acetic acid solution, before and after the desorption, confirmed such result. An environmentally friendly and a low cost material is thus presented, showing the excellent olive pomace potential both in disperse blue adsorption (with an efficiency of 100%) and desorption (with a mean value of 80% for each cycle). Additionally, an alternative environmental friendly use of olive oil solid residues is presented.