synthesis and characterization zns-ni nanoparticles-loaded coconut shell activated carbon for removal of crystal violet: experimental design and optimization

In this work, we used zns-ni/coco ac nanocomposite as a cheap adsorbent for the elimination of crystal violet (cv) dye from an aqueous medium by ultrasound based adsorption method. first zns-ni nanoparticles were synthesized by using microwave assisted co-precipitation method. these nanoparticles were then stabilized on activated carbons derived from coconut shells. the zns-ni/coco ac composite was characterized using x-ray diffraction (xrd), field emission scanning electron microscopy (fesem), transmitted electron microscopy (tem) and energy- dispersive x-ray spectrometry (edx). we used response surface methodology (rsm) based on the central composite design (ccd) to study the effects of four various parameters including dye concentration, the amount of adsorbent, sonication time and ph on the process of adsorption. the optimal condition for removal of cv up to 98.96% was achieved for ph=6.31, 0.023 g of adsorbent for 16.06 mg/ldye concentration and sonication time of 5 minutes. adsorption equilibrium and kinetic data were fitted with the langmuir monolayer isotherm model (qmax=178.57 mg/g and r²= 0.9925) and like pseudo second-order kinetics mechanism (r²=0.9994).