Kinetic Model for the Sorption of Cu (ii) and Zn (ii) Using Lady Fern (Athyrium - Filix – Femina) Leaf Waste Biomass from Aqueous Solution

Abstract

This study presents the biosorption of two divalent metal ions, Cu(ii) and Zn(ii) onto lady fern (Athyrium- filix-femina)        leaf         waste      biomass over        a wide range of reaction conditions and equilibrium sorption kinetics. The rate of removal of Cu(ii) ions and Zn(ii) ions from aqueous solution by
the lady fern leaf waste biomass was studied in batch conditions. The rate of sorption of copper and zinc was rapid within the  initial time of 5-20 minutes and reached a maximum in 30 minutes. Kinetic modelling analysis of the pseudo-first order and pseudo-second order equation model using the linear coefficient of determination R² values showed that the pseudo- second order equation was the  most appropriate model for the description of Cu(ii) and Zn(ii) ion sorption  and can be said to follow a pseudo- second order model. The sorption process was examined by means of Langmuir and Freundlich isotherms. The Langmuir equation revealed  a  monolayer sorption capacity  0.09mg/g  and 0.09mg/ for Cu(ii) and Zn(ii) respectively. The results from this present study indicates that lady fern leaf waste biomass could be employed for the removal of toxic and valuable metals from industrial effluents.

Keywords: Sorption Conditions, Adsorption isotherms and kinetics.