Aluminum foil immersed in alkalized seawater removes Escherichia coli from household drinking water

The contamination of drinking water by pathogens poses a serious health hazard in developing countries. Herein, a simple sanitization tool for drinking water is proposed using layered double hydroxide (LDH), which adsorbs most pathogens with its positive charges. By immersing aluminum foil in a mixture of seawater and NaOH without heating, a Mg–Al type LDH was directly formed and adhered to the surface (LDH foil). An LDH foil of 20 cm2 was shaken in 100 mL of test water containing Escherichia coli (DH5α) for up to 24 h and manually removed from the water. The initial viable count of approximately 103 CFU mL−1 decreased to 14 CFU mL−1 in 1 h, reaching 0.25 CFU mL−1 in 24 h; without the LDH foil, the variation 980–1,270 CFU mL−1. The simplicity in its development and use makes LDH foil a promising tool for sanitizing household water among rural residents.