Point-Of-Use Disinfection of Drinking Water using Cationic Antimicrobial Surface Coatings

One of the most pressing challenges of our time is securing safe water and sanitation to the billions who lack access. Point-of-use (POU) drinking water treatment devices are a promising way to provide water of improved microbial quality where centralized water treatment and distribution infrastructure is unavailable or mismanaged. A promising new potential technology for POU water treatment is antimicrobial filtration using quaternary ammonium silane (QAS) covalently bound to filtration media. These coatings are inexpensive, easy to apply, robust, and effective antimicrobial agents with the potential to be regenerated. Here we evaluate the performance of sands coated with dimethyloctadecyl [3-(trimethoxysilyl)propyl] ammonium chloride at filtering E. coli. Up to 6.1 log removal of E. coli was observed for coated sands, compared to no removal in columns containing uncoated sand. Removal is dependent on filter depth, but insensitive to flow velocity.