Abstract

Nitrate ions (NO3-) enter water sources through sewage and can cause (in high concentrations) methemoglobinemia, cancer of the lymphatic and blood systems. Therefore, the level of NO3- in water must be controlled and effectively reduced. In the present work, copper oxide nanoparticles (CuO -NPs) were synthesized by chemical deposition method and their physicochemical properties have been determined by SEM, FTIR, XRD techniques. CuO-NPs have been used as adsorbents to remove nitrate ions from synthetic effluents. The optimization of nitrate ions removal was performed using response surface modeling (RSM) with parameters (input): initial nitrate concentration (20, 45, 70 mg/L), CuO-NPs concentration (0.03, 0.06, 0.08 g/L), pH (3, 7, 11) and reaction time (40, 80, 120 min). The optimum conditions found were 70 mg/L as nanoparticles dose, 0.08 g/L as NO3- concentration, pH = 3, and 120 min contact time. The analysis of variance for this model confirmed that the model was fitted successfully (R-2 = 0.9987, R-adj(2) = 0.9974). The adsorption fitted to Langmuir isotherm (R-L(2) = 0.9822) and second-order kinetics (R-s2(2) = 0.9999). (C) 2020 Elsevier B.V. All rights reserved.