Equilibrium and kinetics of copper(II) biosorption by Myriophyllum spicatum L

The potential use of Myriophyllum spicatum L. biomass as a biosorbent for the removal of copper(II) from aqueous solution was investigated in laboratory condition. The sorption experiments were undertaken to obtain copper(II) biosorption properties of M. spicatum L., i.e. equilibrium time, the maximum capacity, and rate constants. Copper(II) biosorption was fast and equilibrium was attained within 35 min at initial copper(II) concentration of 6 mg/L. Different isotherm models including the Langmuir, Freundlich, Temkin and Redlich-Peterson model, were used to investigate the sorption capacity and isotherm. These models showed an excellent match with the experimental data except for the Freundlich model. According to the Langmuir coefficients, the maximum sorption capacity of copper onto M. spicatum L. was 10.80 mg/g. The kinetics of copper(II) sorption was also analysed and rate constants were derived. It was found that the overall sorption process was best described by the pseudo second-order equation, and that intraparticle diffusion was not the rate determining step. The results of this study showed that M. spicatum L. can be considered as useful vehicles for the removal and recovery of copper(II) from aqueous solutions.