Equilibrium and Isotherm studies of the biosorption of potentially toxic elements from aqueous solution by Blighia sapida (Akee apple) seeds.

Abstract

The possibility of using Blighia sapida seeds to remove Cu2+, Co2+ and Cd2+ ions from aqueous solutions was explored in this study. The effects of pH, contact time, concentration of metal solution and adsorbent dosages were monitored using Multi-metal batch adsorption technique at 320C. The residual concentrations of the potentially toxic elements were determined using atomic absorption spectrophotometer. The results of the uptake level of the metal ions were found to be dependent on pH of the solution, metal ions type and adsorbent dosage. The adsorption mechanism indicated that biosorption of Co2+ and Cd2+ ion fitted better for Freundlich isotherm while the biosorption of Cu2+ ion was observed to fit well to the Langmuir isotherm. The maximum sorption uptake of the studied metal ions by Blighia sapida seeds was in the order of Cu2+ > Cd2+ > Co2+ ions. This study justifies that Blighia sapida seeds might serve as a viable low cost agricultural waste to remove potentially toxic elements from aqueous solution.