Synthesis and characterization of zero-valent iron nanoparticles and their application for the removal of Reactive Navy Blue SP-BR dye

Zero-valent iron nanoparticle technology is becoming an increasingly popular choice for treatment of hazardous, toxic wastes and for remediation of contaminated sites [1]. In this work, nano scale zero valent iron (NZVI) particles was prepared by the borohydride reduction method [2]. NZVI particles were characterized by transmission electron microscope (TEM) and X-ray diffractometer (XRD). Crystallite size of nanoparticles was calculated from the line broadening of X-ray diffraction peak according to the Sherrer formula. The calculated crystallite size for Fe0 nanoparticles were approximately 11 nm. The efficiency of synthesized NZVI particles in the removal of environmental pollutants was investigated by decolorization of Reactive Navy Blue SP-BR dye solution as a model pollutant. Dye solution was substantially reduced with synthesized NZVI particles under varied conditions of experimental variables such as NZVI dosage, initial dye concentration and pH. The experimental results exhibited pseudo first-order kinetics for dye removal by NZVI particles. The reaction rate constant (kobs), increased with decreasing pH from 10 to 3, and with increasing Fe0 nanoparticles dosage from 0.1 to 0.3 g L-1. Also, with increasing the initial dye concentration from 0.01 to 0.05 g L-1 the removal efficiency decreased.