Utilization of iron oxide coated natural zeolite for the removal nitrate from fresh water

Abstract

A research on adsorption of nitrate in fresh water using iron oxide coated natural zeolite has been conducted. This research aims to examine the ability of iron oxide coated natural zeolite in nitrate adsorption. The characterization of iron oxide coated natural zeolite was analyzed using X-Ray Diffraction (XRD) method and Infra Red (IR) spectrophotometry. Some adsorption parameters i.e. initial pH, adsorption isotherm and adsorption kinetics were examined in the adsorption processes. The concentration of nitrate was measured quantitatively by sodium salicylate method. The results show that FT-IR spectrogram of iron oxide coated natural zeolite that typical fingerprint of adsorbent material with Fe-O group. The XRD pattern shows that adsorbent material has coated by iron oxide (β-Fe-OOH). The optimum removal of nitrate when the initial pH 6.65. The adsorption capacity and average adsorption energy were estimated from Dubinin-Radushkevich isotherm model. The adsorption capacity of iron oxide coated natural zeolite in freshwater was 1.05x10−1 mmol/g. The average adsorption energy in freshwater was 1.89 kJ/mol. The results indicated that nitrate adsorption using natural zeolite coated iron oxide was dominated by physical adsorption. Nitrate adsorption in freshwater was best described by pseudo first order kinetic model with k1 value of 4.90 × 10−3/minutes.