MIL-53(Al): An Efficient Adsorbent for the Removal of Nitrobenzene from Aqueous Solutions

Abstract

MIL-53(Al), hydrothermally synthesized and purified by solvent extraction, was used as adsorbent for the removal of nitrobenzene from aqueous solution. Pristine MIL-53(Al) and MIL-53(Al) loaded with various amounts of nitrobenzene were characterized by X-ray diffraction analysis with cell indexation study, thermogravimetric analysis, Fourier transform infrared spectroscopy, and BET surface area. A simulation study of nitrobenzene adsorption on MIL-53(Al) was performed. The adsorption study of nitrobenzene on MIL-53(Al) was carried out at 30 ± 1 °C using batch experiments. The amount of nitrobenzene adsorbed decreases with an increase in the temperature from 30° to 60 °C and pH from 8 to 11, whereas no significant difference was observed in acidic pH. The adsorption data were fitted to Sips and Redlich–Peterson isotherm models. The adsorption capacity of nitrobenzene on MIL-53(Al) obtained was 610 mg/g, higher than that of zeolites (267.2 mg/g) and organoclays (100 mg/g), but, lower than that of modified commercial activated carbons (1443.53 mg/g).