Biosorption of Heavy Metals from Aqueous Solutions Using Water Hyacinth as a Low Cost Biosorbent

Abstract

In this study, biosorption of Cu(II) and Zn(II) ions from aqueous solutions by water hyacinth fiber was investigated as a function of initial solution concentration, initial biomass concentration and temperature. Solutions containing copper and zinc ions were prepared synthetically in single component and the time required for attaining adsorption equilibrium was studied. The optimum sorption conditions were studied for each metal separately. The adsorption equilibrium data were adequately characterized by Langmuir, Freundlich, Temkin and Dubinin-Radushkevich equations. The equilibrium biosorption isotherms showed that water hyacinth possess high affinity and sorption capacity for Cu(II) and Zn(II) ions, with sorption capacities of 99.42 mg Cu²⁺ and 83.01 mg Zn²⁺ per 1 g biomass, respectively. All results showed that water hyacinth fiber is an alternative low cost biosorbent for removal of heavy metal ions from aqueous media.

Keywords: biosorption, low cost biosorbent, wastewater treatment, heavy metal