Performance Evaluation of Nanoscale Zero-Valent Iron Adsorbed on Calcium Alginate in Nitrate Reduction in Aqueous Systems

There is nowadays a growing concern about nitrate pollution in groundwater resources and its adverse impacts on the public health. The present experimental study was conducted to evaluate the efficiency of the Fe° calcium alginate process in nitrate reduction. For this purpose, the effect of Fe° adsorbed on calcium alginate on nitrate oxidation was investigated at a pH range of 2 to10, a contact time of 10 to 90 min, nitrate concentrations of 50 to 300 mg/L and with calcium alginat concentrations of 0.5, 1, and 2 mg/L. Nitrate level in the effluent was measured using spectrophotometry. Results showed that a pH level of 3 and a contact time of 15 min were the optimal values in the Fenton process for nitrate removal. Under these conditions, nitrate removal efficiencies for FeШ, FeІІ, Fe°, FeІІ/Fe°/H2O2, and FeШ/Fe°/H2O2 were 10.5, 27.6, 36.5, 62.3, and 74%, respectively, for a retention time of 90 min, an initial nitrate concentration of 100 mg/L, an iron concentration of 10 mg/L, and a pH level of 4. The results indicate that the corrective fenton process with zero iron nano-particles can effectively reduce nitrate under optimal conditions and that this method can be successfully used for the removal of similar compounds.