Disinfection effect of hydrotalcite compounds containing antimicrobial metals against microorganisms in water

Abstract

Hydrotalcites containing copper (Cu-HT) were synthesized using MgCl2, AlCl3 and CuCl2, and hydrotalcites containing zinc (Zn-HT) were synthesized using MgCl2, AlCl3 and ZnCl2. Their disinfection activities against Escherichia coli, Staphylococcus aureus and E. coli phage Q β (phage Q β) were investigated by the shake-flask method. Cu-HT possessed strong disinfection activities against E. coli and phage Q β, whereas Zn-HT showed bactericidal activity against E. coli, S. aureus and phage Q β. Copper elution from Cu-HT was undetectable during the disinfection test. The disinfection activity of Cu-HT was due to the presence of copper. The pH of Cu-HT suspensions was pH 9.3 as a result of the hydration reaction at the surfaces of the Cu-HT particles. The remarkable disinfection activity of Cu-HT against phage Q β seemed to be based on the cooperative action of copper in Cu-HT and the direct contact of phage Q β cells to the hydroxyl layers on the surfaces of the Cu-HT particles. We propose that Cu-HT can be used as an alternative disinfectant to chlorine in a water purification system.