Sythesis of Nano Zerovalent Iron Supported Sawdust (NZVI/SD) and Its Application for Removal of Arsenic (III) from Aqueous Solution
Tasrina R. Choudhury
Analytical Chemistry Laboratory (ISO/IEC 17025:2005 Accredited), Chemistry Division, Atomic Energy Centre, Bangladesh Atomic Energy Commission, Dhaka 1000, Bangladesh.
Snahasish Bhowmik
Department of Applied Chemistry and Chemical Engineering, Noakhali Science and Technology University, Noakhali, Bangladesh.
M. S. Rahman
Atmospheric and Environmental Chemistry Laboratory, Chemistry Division, Atomic Energy Centre, Bangladesh Atomic Energy Commission, Dhaka 1000, Bangladesh.
Mithun R. Nath
Department of Applied Chemistry and Chemical Engineering, Noakhali Science and Technology University, Noakhali, Bangladesh.
F. N. Jahan
Department of Applied Chemistry and Chemical Engineering, University of Dhaka, Dhaka 1000, Bangladesh.
B. A. Begum
Atmospheric and Environmental Chemistry Laboratory, Chemistry Division, Atomic Energy Centre, Bangladesh Atomic Energy Commission, Dhaka 1000, Bangladesh.
Mohammad Nurnabi *
Department of Applied Chemistry and Chemical Engineering, University of Dhaka, Dhaka 1000, Bangladesh.
*Author to whom correspondence should be addressed.
Abstract
Sawdust supported nano-zerovalent (NZVI/SD) iron was synthesized by treating sawdust with ferrous sulphate followed by reduction with NaBH4. The NZVI/SD was characterized by SEM, XRD, FTIR and Chemical method. Adsorption of As (III) by NZVI/SD was investigated and the maximum uptake of As (III) was found at pH value of 7.74 and equilibrium time of 3 hrs. The adsorption isotherm modelling revealed that the equilibrium adsorption data were better fitted with the Langmuir isotherm model compared with the Freundlich Isotherm model. This study revealed that the maximum As (III) ions adsorption capacity was found to be 12.66 mg/g for using NZVI/SD adsorbent. However, the kinetics data were tested by pseudo-first-order and pseudo-second-order kinetic models; and it was observed that the adsorption data could be well fitted with pseudo-second-order kinetics for As (III) adsorption onto NZVI/SD depending on both adsorbate concentration and adsorption sites. The result of this study suggested that NZVI/SD could be developed as a prominent environment-friendly adsorbent for the removal of As (III) ions from aqueous systems.
Keywords: Sawdust, nano zerovalent iron, adsorption, isotherm, kinetics