Porous
Ceramic Tablet Embedded with Silver Nanopatches
for Low-Cost Point-of-Use Water Purification
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Abstract
This work describes a novel method
to embed silver in ceramic porous
media in the form of metallic silver nanopatches. This method has
been applied to develop a new POU technology, a silver-infused ceramic
tablet that provides long-term water disinfection. The tablet is fabricated
using clay, water, sawdust, and silver nitrate. When dropped into
a household water storage container, the ceramic tablet releases silver
ions at a controlled rate that in turn disinfect microbial pathogens.
Characterization of the silver-embedded ceramic media was performed
using transmission electron microscopy. Spherical-shaped patches of
metallic silver were observed at 1β6 nm diameters and confirmed
to be silver with energy dispersive spectroscopy. Disinfection experiments
in a 10 L water volume demonstrated a 3 log reduction of Escherichia coli within 8 h while silver levels remained
below the World Health Organization drinking water standard (0.1 mg/L).
Silver release rate varied with clay mineralogy, sawdust particle
size, and initial silver mass. Silver release was repeatable for daily
10 L volumes for 154 days. Results suggest the ceramic tablet can
be used to treat a range of water volumes. This technology shows great
potential to be a low-cost, simple-to-use water treatment method to
provide microbiologically safe drinking water at the household level