Optimization of nitrate reduction by EDTA catalyzed zero-valent bimetallic nanoparticles in aqueous medium.

The present study aims to investigate the EDTA catalyzed reduction of nitrate (NO (3) (-) ) by zero-valent bimetallic (Fe-Ag) nanoparticles (ZVBMNPs) in aqueous medium and to enumerate the effect of temperature, solution pH, ZVBMNPs dose and EDTA concentration on NO (3) (-) reduction. Batch experimental data were generated using a four-factor Box-Behnken design. Optimization modeling was performed using the response surface method for maximizing the reduction of NO (3) (-) by ZVBMNPs. Significance of the independent variables and their interactions were tested by the analysis of variance and t test statistics. The model predicted maximum reduction capacity (340.15 mg g(-1) NO (3) (-) ) under the optimum conditions of temperature, 60 °C; pH 4; dose, 1.0 g l(-1); and EDTA concentration, 2.0 mmol l(-1) was very close to the experimental value (338.62 mg g(-1)) and about 16 % higher than the experimentally determined capacity (291.32 mg g(-1)). Study demonstrated that ZVBMNPs had higher reduction efficiency than Fe(0) nanoparticles for NO (3) (-) . EDTA significantly enhanced the NO (3) (-) reduction by ZVBMNPs. The EDTA catalyzed reduction of NO (3) (-) by ZVBMNPs can be employed for the effective decontamination of water.