adsorption properties of nickel oxide nanoparticles for removal of congo red from aqueous solution

the effective removal of dyes from aqueous wastewaters is among the most important issues formany industrialized countries. removal of congo red (cr) dye from aqueous solutions was studiedusing nickel oxide nanoparticles. the operating variables studied were initial ph of solution,adsorbents dosage, temperature and contact time. the morphological information of nickel oxidenanoparticles were characterized using scanning electron microscopy (sem) and x-raydiffractometer (xrd). the adsorbent exhibits high efficiency for cr adsorption and equilibrium canbe achieved in 25 min. in order to investigate the efficiency of cr adsorption on nickel oxidenanoparticles, pseudo-first-order, pseudo-second-order kinetic models were studied. it was observedthat the pseudo-second-order kinetic model fits better than other kinetic model with good correlationcoefficient. equilibrium data were fitted to the langmuir model.