Removal of Cu (II), Zn (II) and Ni (II) using acai residue (Euterpe oleracea Mart.) as a biosorbent in aqueous solution

Removal of transition metal ions such as Cu(II), Zn(II) and Ni(II) from aqueous solutions was investigated using acai residual biomass (Euterpe oleracea Mart.) as a biosorbent. The characterization of sample was performed by SEM/EDS image and point of zero charge (pH(PCZ)). The influence of pH, contact time and initial metal concentration was evaluated. The adsorption process was studied by the models of isotherms of Langmuir and Freundlich. The pseudo first and second order kinetic models were considered to interpret the experimental data. The maximum sorption capacity determined was 15.77, 24.69 and 3.30 mg g(-1), respectively for Cu(II), Zn(II) and Ni(II). The biosorption followed pseudo second order kinetic. The adsorption process of the Cu(II), Zn(II) and Ni(II) ions is favorable and spontaneous.