Efficient removal of azo dyes from water with chitosan/carbon nanofloas a novel nanocomposite synthesized by pyrolysis technique

Abstract

In this study, chitosan/carbon nanoflowers as a novel nanocomposite were synthesized via spray pyrolysis technique for dye removal from water. To examine the characteristics of pure and dye-loaded nanocomposite, field emission scanning electron microscopy, zeta potential, and Fourier transform infrared spectroscopy analyses were performed. The adsorption studies were conducted in batch mode for the removal of two azo dyes, Acid Black1 (AB1) and Congo red (CR), from aqueous solution. The effect of principal factors such as solution pH, contact time, adsorbent dosage, temperature, initial dye concentration, and ionic strength on dye adsorption was optimized. The equilibrium was found to be achieved in 60 min at 25°C, and the pseudo-second-order model provided the best fit to the experimental data. Maximum adsorption capacities of AB1 and CR were found to be 259.13 and 553.12 mg g −1 , respectively (according to Langmuir model under initial dye concentration of 400 mg L –1 at pH = 6.75).