Preparation of surface modified montmorillonite and its application for adsorption of phenolic compounds from olive mill wastewater

To recover phenolics from olive mill wastewater (OMW), adsorption was performed and compared among raw montmorillonite (Mt) and three modified-Mt forms. The Mt was modified with tetradecyl trimethylammonium bromide (TTB), cetyl trimethylammonium bromide (CTB), and didodecyl dimethylammonium bromide (DDB). The effect of adsorption time, pH and adsorbent concentration on the adsorption efficiency (AE) of phenolics from OMW were investigated. Experimental results revealed that the maximum AE% (93.43%) of TTB-Mt-1 was obtained at pH = 4.7, adsorbent concentration of 0.66 g/L. The Mt and TTB-Mt-1 before and after adsorption in optimum situation were characterized by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy in order to establish the adsorption behavior-properties relationship. The results show there was successful phenolics adsorption on TTB-Mt-1. The equilibrium data of adsorbed phenolics was fitted well to Langmuir models and the kinetic data indicated that the best fit of experimental data was pseudo-second order model.