Synthesis and Characterization of Organophilic Bentonite for Produced Water Treatment

Abstract

This study investigates the synthesis and characterization of organophilic bentonite, from natural organophobic bentonite from Ebenebe Anambra State, Nigeria. The clay was used after milling and drying at 110°C overnight. The natural bentonite was then converted to sodium bentonite via ion exchange process using sodium carbonate. The Sodium exchanged bentonite (SEB) was modified through incipient wetness impregnation and ion exchange technique with dimethyldioctadecylammonium bromide (DMDOA) to obtain organophilic bentonite. The mineralogical characteristic of the clays was determined before and after modification using Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Fluoresence (XRF). Different organic solvents, namely kerosene, diesel, gasoline, xylene, ethyl benzene and toluene, were used to investigate the organophilic nature as well as the adsorption capacity of the modified bentonite. The XRF result showed from the Si/Al ratio that modification did not affect the basic structure of the bentonite. The FTIR result showed bands which are attributable to asymmetric and symmetric stretching vibration of CH2 group of the alkyl chains present in DMDOA. Another band was also assigned to the asymmetric angular deformation of the CH3 group of dimethyl ammonium quaternary group. The modified samples showed higher affinity as well as higher sorption capacity to organic solvents compared to SEB and the order of adsorption capacity for these organics are diesel > kerosene > gasoline and toluene > ethylbenzene > xylene. The results show that the organophilic bentonite clay has potential for the removal of organics in produced water.