Optimization of preparation of montmorillonite nanometer zero-valent iron and the degradation of amoxicillin by response surface methodology

Three-factor and three-level tests were carried out by Box–Behnken response surface methodology, with amoxicillin as the target pollutant, nanometer zero-valent iron (nZVI) materials loaded with montmorillonite prepared by liquid phase reduction method and the concentration of FeSO4 and NaBH4 and montmorillonite dosage as influencing factors. It revealed that the interaction between FeSO4 concentration and NaBH4 concentration had a significant effect on the preparation of montmorillonite-loaded nanometer zero-valent iron material, playing a key role in the removal of amoxicillin, and the effect of FeSO4 concentration was even more significant. In addition, the shape, structure and characteristic groups of the prepared materials were analyzed by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), etc. The nanometer zero-valent iron loaded with montmorillonite can effectively slow down the nZVI agglomeration effect and improve the effect of material degradation of pollutants. For the same concentration of amoxicillin wastewater, the removal rate of amoxicillin wastewater, after 1 h reaction, is as follows: Mont/nZVI> nZVI>Mont. The optimal conditions for the reaction are: pH is 3, the initial concentration is 60 mg/L, and the dosage is 2 g/L. The higher the temperature, the more amoxicillin is degraded by Mont/nZVI.