Comparison of modified boehmite nanoplatelets and nanowires for dye removal from aqueous solution

In this study, boehmite (-Al00H) nanoplatelets and nanowires were synthesized at a pH of 5 and 12, respectively, modified with sulfonic acid (Al00H-SA5), (Al00H-SAl2), and were used to adsorb eriochrome black T (EbT) dye solutions. Transmission electron microscopy, scanning electron microscopy, Fourier-transform infrared spectroscopy and X-ray diffraction were used to characterize the prepared nanoplatelets and nanowires. The effect of many parameters including initial concentration, pH and contact time was investigated. Values of 212.76 and 116.28 mg g(-1) were, respectively, obtained for Al00H-SA5 and Al00H-SAl2 for the adsorption maximum of EbT. Compared between two structures, the results indicated that the optimum conditions for 100 mg L-1 EbT solution were pH of 3 and 0.5 g L-1 Al00H-SA5 as well as pH of 3 and 1 g L-1 Al00H-SAl2. Results of adsorption isotherms and adsorption kinetics indicated which they better matched by the Langmuir isotherm and also the adsorption kinetics better described by the pseudo -second-order model. Thermodynamic parameters have been measured, and results indicate that the adsorption process was spontaneous and exothermic for Al00H-SAl2 and nonspontaneous and endothermic for Al00H-SA5. Finally, Al00H-SA5 is a suitable adsorbent than that of Al00H-SAl2 and can be used for dye removal in wastewater treatment processes.