USE OF A LOW-COST AGRICULTURAL BY-PRODUCT FOR THE ADSORPTION OF TOTAL PHENOLS CONTAINED IN OLIVE-MILL WASTEWATER

摘要

The purpose of this research was to investigate the adsorption of total phenols, contained in olive-mill wastewater, on solid by-products of olive pomace processing mills. Preliminary batch experiments were conducted using three different types of olive pomace, dried olive pomace (OP-1), dried and solvent extracted olive pomace (OP-2) and dried, solvent extracted and incompletely combusted olive pomace (OP-3). According to the results, OP-1 and OP-2 could not be used as adsorbents due to their tension to desorb total phenols that were already contained in their mass. On the other hand, OP-3 showed high performance for total phenols adsorption and stability. Further experiments revealed that increase of OP-3 concentration, not only increased total phenols removal efficiency, but additionally wastewater's pH, possibly due to the basic character of this adsorbent. Moreover, total phenols removal efficiency was increased with increasing solution's pH and decreasing particle size of the adsorbent material. Preliminary fixed bed adsorption experiments were also conducted on OP-3 columns and the breakthrough curves were determined by varying flow rate. Lower flow rates resulted in longer column saturation/exhaustion time.