Utilization of bare MgO, CeO2, and ZnO nanoparticles for nitrate removal from aqueous solution

Abstract

The traditional drinking water purification process is inefficient in removing nitrate significantly. Adsorption can be the most practical method for the removal of nitrate from drinking water. In this study, novel MgO, CeO2, and ZnO nanoparticles (NPs) were utilized for nitrate removal. The MgO, CeO2, and Zn NPs were characterized by Fourier transform infrared spectrometry (FT‐IR), scanning electron microscopy‐energy disperse X‐ray (SEM‐EDX), and X‐ray diffractometer (XRD) analysis. The efficiency of nitrate removal was examined through batch adsorption experiments. The influence of various parameters was studied, namely pH (3–8), temperature (15–40°C), time (10–1440 min), and liquid/solid weight ratio (L/S =25 mL/0.025 g). The optimum conditions from mentioned parameters were used in isotherm experiments with initial nitrate concentration (22–220 mg/L). The adsorption kinetics and isotherm data obeyed well Pseudo‐second‐order and linear and Freundlich models, indicating the multi layer‐chemisorption of nitrate ions. The maximum adsorption capacities of nitrate (N‐ ) calculated by final point of isotherm experiments were 86.4 mg/g for MgO, 57.6 mg/g for ZnO, and 58.6 mg/g for CeO2. The thermodynamic parameters ( S°) were evaluated. From the thermodynamic parameters, it is suggested that the adsorption of nitrate on NPs followed the endothermic and spontaneous processes. The desorption potential of MgO, CeO2, and ZnO also showed the stability and reusability. Our findings also revealed that among studied NPs from this study and literature MgO NPs is potentially the best adsorbent for removal of nitrate from aqueous solutions. © 2018 American Institute of Chemical Engineers Environ Prog, 37: 1901–1907, 2018