Adsorptive removal of crystal violet dye by a local clay and process optimization by response surface methodology

Abstract

The current study relates to the removal of a dye [crystal violet (CV)] from aqueous solutions through batch adsorption experiment onto a local clay from Morocco. The clay was characterized by X-ray diffraction, IR spectroscopy, X-ray fluorescence, scanning electron microscope, Brunauer–Emmett–Teller analysis and Fraunhofer diffraction method. The influence of independent variables on the removal efficiency was determined and optimized by response surface methodology using the Box–Behnken surface statistical design. The model predicted maximum adsorption of 81.62% under the optimum conditions of operational parameters (125 mg L−1 initial dye concentration, 2.5 g L−1 adsorbent dose and time of 43 min). Practically, the removal ranges in 27.4–95.3%.