NITRITE REMOVAL FROM AQUEOUS SOLUTION USING SURFACE MODIFIED MAGHEMITE NANOPARTICLES

Abstract

In the present work, maghemite nanoparticles (MNP) was synthesized by a simplified method and then modified by sodium dodecyl benzene sulfonate (NaDBS) for the removal of nitrite from aqueous solution. The prepared nanoparticles were characterized by Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The SEM image and XRD analysis showed that the average particle size and crystallite of the maghemite nanopaticles are ca. 32.7 nm and 33.5 nm, respectively. Different parameters namely, pH of the adsorption solution, adsorbent dosage and spectrophotometric reagents were optimized. Spectrophotometric determination of nitrite in an optimized condition showed that the MNP is able to deplete over 88% of nitrite from the initial solution. Moreover, dynamic adsorption study per se confirmed the shortest necessary contact time (ca. 6 min) in the adsorption process of nitrite which is quite encouraging from a practical and industrial point of view. The kinematic study revealed that the nitrite adsorption is a pseudo-first-order process. In addition, two different models (Freundlich- and kinetic-type model) were developed for the adsorbent dosage effect on nitrite adsorption. A Freundlich-type model manifested high coefficients of regression, indicating its robustness.