Removal of crystal violet by Cu-chitosan nano-biocomposite particles using Box-Behnken design

Copper nanoparticles (CuNPs) impregnated biocomposites (Cu/chit-NBC) were prepared and characterized by the state-of-the-art analytical techniques. The CuNPs were in the average size ranges of 45.6-63.7 nm and 86.4 nm as confirmed by scanning electron microscopy and dynamic light scattering, respectively. To decolorize the crystal violet from the aqueous medium, fabricated Cu/chit-NBC was applied as an adsorbent. Box-Behnken design using three independent variables was adopted to optimize the Crystal Violet (CV) decolorization process. Under the optimum conditions of temperature 42.7 degrees C, pH 9.5, and 149.9 mg L-1 dose of adsorbent, 99.7 +/- 0.2% decolorization was observed. Cu/chit-NBC also showed a very high dye removal capacity in simulated industrial textile effluents of around 99.7 +/- 0.2%. The CV decolorization was consistent with pseudo-second-order kinetics and best fitted with the Freundlich adsorption isotherm. The nature and the potential processes involved in interactions between the CV and the nano-bioadsorbents during discoloration have been discussed in this paper.