Mohamad Hajar - Chemical Engineering Department, AmirKabir University of Technology (Tehran Polytechnic

The mercury biosorption onto powdered leaves of Eriobotrya japonica was investigated in a batch adsorption system. The metal removal was rapid, with more than 80% of total biosorption taking place in 30 min, and equilibrium was achieved at around 60 min. The maximum biosorption capacity of mercury was found to be 48.2 mg/g at optimum pH 5. The applicability of two kinetic models including pseudo-first order and pseudo-second order model was tested to elucidate the biosorption mechanism. The kinetics of biosorption followed pseudo-second order model. The Langmuir and Freundlich isotherm models were used to explain the equilibrium data for mercury-biosorbent system. The Langmuir model showed better fit of data with correlation coefficient of 0.99. The results demonstrated that the leaf powder of Eriobotrya japonica could be used as an efficient and low-cost biosorbent for the removal of mercury ions from contaminated aqueous environment.

Biosorption, Eriobotrya japonica, Mercury removal, Equilibrium, Kinetics