Removal of cadmium(II) by mycelial pellet of rhizopus oryzae from aqueous solution

Mycelial pellet of Rhizopus oryzae was applied as a potential biosorbent for the removal of cadmium(II) from aqueous solution. The effects of pellet diameter, pH, contact time, temperatures and initial metal concentration were studied. The optimum diameter and pH were 1.0-1.2 mm and 4.5. SEM study indicated that the structure of mycelial pellet of Rhizopus oryzae could enhance adsorption active sites and provided an advantageous condition for attracting more cadmium(II) around sites. Evaluation of the kinetics data showed that the adsorption followed the pseudo-second order dynamics well. The calculated thermodynamic parameters (δG°, δH° and δS°) showed that the adsorption was feasible, spontaneous and endothermic. The equilibrium data fitted well to the Langmuir adsorption model.