Influence of <i>Ficus religiosa</i> leaf powder on bisorption of cobalt

Abstract

The batch-wise biosorption of cobalt by <i style="">Ficus religiosa</i> (peepul) leaf powder has been carried out. The optimum biosorbent dosage is 60 g/L for an equilibrium agitation time of 90 min. Percentage removal of cobalt is increased from 70.9 to 97.2 (0.96 to 1.45 mg/g) with decrease in acidity in the <i style="">p</i>H range from 2 to 7. The experimental data are well represented by Freundlich (<i style="">n</i>=0.42, <i style="">K_f</i>=0.83 L/g, <i style="">R²</i>=0.948), Langmuir (<i style="">R_L</i>=0.566, <i>q</i>_m= 3.60 mg/g, <i style="">R²</i>=0.991), Redlich-Peterson(<i style="">R²</i>=0.98) and Temkin (<i style="">R²</i>=0.98, b_T =784.52) isotherms, indicating favourable biosorption. The biosorption of Co(II) is described by the pseudo-second order rate equation (<i style="">K</i>=0.418 g/mg-min, <i style="">R²</i>=0.99) preferably than first order rate equation (<i style="">R²</i>=0.89). The biosorption is exothermic, irreversible and spontaneous.