Using Quartz-Supported Zero-Valent Iron Nanoparticles for Removing Nitrate in Equilibrium and Fluid Systems

Document Type : Complete scientific research article

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Abstract

Nitrate anion is an important ground- and surface-water contaminant, around the world. High nitrate concentration could damage the human respiratory and digestive systems; thus, controlling nitrate transfer toward water resources and reducing its concentration is essential to protect human health and the environment. In this research, effect of coating zero-valent iron nanoparticles on quartz (Q-Fe0Nps) and possible retrieving and reusing them were evaluated for removing nitrate from aqueous solution. Fe0Nps were made by chemical reduction method and supported by quarts. Fe0Nps efficiency for removing nitrate was assessed in both equilibrium and fluid systems as function of nitrate and Fe0 concentrations. Results indicated that in appropriate Fe0Nps concentration, 100% of nitrate can be removed. Coating Fe0Nps on quartz surface enhanced their efficiency for nitrate reduction more than 10 folds. Experimental data at 50 and 100 mg/L initial nitrate concentrations indicated that approximately 0.57 mmol nitrate is reduced by 1 mmol Fe0Nps. In addition, measuring nitrate reduction in fluid systems demonstrated that Fe0Nps react with nitrate ion quickly, which makes them relevant for using in fluid systems like ground-water. In addition, retrieved Q-Fe0Nps could reduce nitrate almost as well as the original particles, which reduces the cost for using in decontamination plans.

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