Multi-Component Adsorption of Benzene, Toluene, Ethylbenzene, and Xylene from Aqueous Solutions by Montmorillonite Modified with Tetradecyl Trimethyl Ammonium Bromide

H Nourmoradi,M Nikaeen,Mehdi Khiadani

doi:10.1155/2013/589354

Abstract

Multicomponent adsorption of benzene, toluene, ethylbenzene, and xylene (BTEX) was assessed in aqueous solutions by montmorillonite modified with tetradecyl trimethyl ammonium bromide (TTAB-Mt). Batch experiments were conducted to determine the influences of parameters including loading rates of surfactant, contact time, pH, adsorbate concentration, and temperature on the adsorption efficiency. Scanning electron microscope (SEM) and X-ray diffractometer (XRD) were used to determine the adsorbent properties. Results showed that the modification of the adsorbent via the surfactant causes structural changes of the adsorbent. It was found that the optimum adsorption condition achieves with the surfactant loading rate of 200% of the cation exchange capacity (CEC) of the adsorbent for a period of 24 h. The sorption of BTEX by TTAB-Mt was in the order ofB<T<E<X. The experimental data were fitted by many kinetic and isotherm models. The results also showed that the pseudo-second-order kinetic model and Freundlich isotherm model could, respectively, be fitted to the experimental data better than other available kinetic and isotherm models. The thermodynamic study indicated that the sorption of BTEX with TTAB-Mt was achieved spontaneously and the adsorption process was endothermic as well as physical in nature. The regeneration results of the adsorbent also showed that the adsorption capacity of adsorbent after one use was 51% to 70% of original TTAB-Mt.

Highlights

Petroleum hydrocarbons such as BTEX are one of the most common pollutants that cause environmental pollution [1]. ese compounds are volatile monoaromatic hydrocarbons that are present in petroleum, gasoline, and industrial solvents [2]
E physical and chemical characteristics of the adsorbent are presented in Table 1. e Scanning electron microscope (SEM) images of the Raw-Mt and trimethyl ammonium bromide (TTAB)-Mt are presented in Figures 1(a) and 1(b). e surface structure of the adsorbent is changed by the modi cation with TTAB
The surface morphology of the TTAB-Mt is smoother than Raw-Mt. is is due to the fact that the porous surface of Raw-Mt is lled with surfactant. e adsorbent modi cation by TTAB leads to reduction of the surface area from 32.6 m2/g to 26.2 m2/g for Raw-Mt and TTAB-Mt, respectively

Summary

Introduction

Petroleum hydrocarbons such as BTEX (benzene, toluene, ethylbenzenem and xylene) are one of the most common pollutants that cause environmental pollution [1]. ese compounds are volatile monoaromatic hydrocarbons that are present in petroleum, gasoline, and industrial solvents [2]. BTEX has harmful effects on the human health that lead to cancer, mucosal membranes irritation, impairment of the central nervous system, and liver and kidney disruption [5, 6]. Due to these adverse health effects, removal of BTEX from water and wastewater is essential. Because of its high surface area, low cost, being eco-friendly, and nontoxicity, has a good efficacy in the Journal of Chemistry adsorption of various pollutants in aqueous solutions [19,20,21,22]. A type of clay, was modi ed by TTAB and used to remove BTEX from aqueous solution

Materials and Methods

Results and Discussion

Conclusion