Inactivation of Escherichia coli in water by silver-coated Ni0.5Zn0.5Fe2O4 magnetic nanocomposite: a Box–Behnken design optimization

Abstract

Abstract The present research studied the antibacterial effect of silver-coated Ni0.5Zn0.5Fe2O4 magnetic nanoparticles on Gram-negative bacteria Escherichia coli (E. coli) from water. The effects of pH (6, 7 and 9), disinfectant dose (2, 5 and 10 g/L) and contact time (10, 20 and 30 min) have been also investigated. To obtain important factors, the interactions between factors and optimal experimental design in surface response method were used based on Box–Behnken design. According to the research findings, the system is efficient in eliminating E. coli. The results showed that E. coli elimination efficiency intensified through increasing the amount of nanoparticles from 2 to 10 g/L. The results also demonstrated no significant change in E. coli elimination through pH increasing of 6 to 9. Expanding contact time from 10 to 30 min also heightened E. coli elimination rate. R 2 for E. coli elimination is 0.9994 indicating a good agreement between model experimental data and forecasting data.

Keywords

• Magnetic nanoparticles
• Escherichia coli
• Silver nanoparticles
• Box–Behnken design