Biosorption of copper(II) from aqueous solutions by wheat shell

The adsorption capacity of wheat shell for copper (11) was studied at various pH (2-7), agitation speeds (50250 rpm) and initial metal ion concentrations (Co, from 10 to 250 mg.L-1). Maximum biosorption of copper onto wheat shell occurred at 240 rpm agitation speed and at pH between 5 and 6. The biosorption values of copper (11) were increased with increasing pH from 2 to 5 and decreased with increasing copper/wheat shell (x/m) ratios from 0.83 to 10.84 mgCu(II).g(-1) wheat shell. The biosorption efficiencies at these x/m ratios were 99% and 52%, respectively, at the end of the 120 min contact time (t). The equilibrium isotherms and kinetics were obtained from batch adsorption experiments at 298 K. It was observed that wheat shell was a suitable biosorbent for removing Cu(II) from aqueous solutions.