TY - JOUR
T1 - Alkali-Activated Foams Coated with Colloidal Ag for Point-of-Use Water Disinfection
AU - Bhuyan, Mohammad Amzad Hossain
AU - Karkman, Antti
AU - Prokkola, Hanna
AU - Chen, Boyu
AU - Perumal, Priyadharshini
AU - Luukkonen, Tero
PY - 2024
Y1 - 2024
N2 - Alkali-activated foams are ceramic-like materials prepared at near-ambient temperature. This study investigates them for point-of-use water disinfection, thus providing an alternative to ceramic filters fired at a high temperature. Alkali-activated foams with different compositions were characterized for the porosity, mechanical strength, shrinkage, and microstructure. The optimized foam, employing metakaolin as the raw material, was coated with a colloidal Ag solution. The disinfection performance and leaching behavior of the foams was followed in a continuous 10 week experiment, where clean water with a weekly pulse of contaminated water was distributed through the foam. The average inactivation of Escherichia coli with the Ag-coated foam was 2.84 log10, which was 1.27 units higher compared to foam without Ag. A quantitative polymerase chain reaction analysis and metagenomic sequencing verified that foams with and without Ag were both capable of reducing the microbial load. Furthermore, the changes induced by the foam with Ag on the microbial community composition, antibiotic resistome, and metal and biocide resistomes were significant. The leached concentrations of Ag, Na, Si, and Al were in accordance with the drinking water guidelines. Finally, a life cycle assessment indicated the possibility of reducing the global warming potential and the total embodied energy in comparison with a conventional ceramic filter.
AB - Alkali-activated foams are ceramic-like materials prepared at near-ambient temperature. This study investigates them for point-of-use water disinfection, thus providing an alternative to ceramic filters fired at a high temperature. Alkali-activated foams with different compositions were characterized for the porosity, mechanical strength, shrinkage, and microstructure. The optimized foam, employing metakaolin as the raw material, was coated with a colloidal Ag solution. The disinfection performance and leaching behavior of the foams was followed in a continuous 10 week experiment, where clean water with a weekly pulse of contaminated water was distributed through the foam. The average inactivation of Escherichia coli with the Ag-coated foam was 2.84 log10, which was 1.27 units higher compared to foam without Ag. A quantitative polymerase chain reaction analysis and metagenomic sequencing verified that foams with and without Ag were both capable of reducing the microbial load. Furthermore, the changes induced by the foam with Ag on the microbial community composition, antibiotic resistome, and metal and biocide resistomes were significant. The leached concentrations of Ag, Na, Si, and Al were in accordance with the drinking water guidelines. Finally, a life cycle assessment indicated the possibility of reducing the global warming potential and the total embodied energy in comparison with a conventional ceramic filter.
KW - alkali-activated materials
KW - geopolymers
KW - point-of-use water treatment
KW - water disinfection
KW - water supply
UR - http://www.scopus.com/inward/record.url?scp=85183026598&partnerID=8YFLogxK
U2 - 10.1021/acsestwater.3c00711
DO - 10.1021/acsestwater.3c00711
M3 - Article
AN - SCOPUS:85183026598
SN - 2690-0637
VL - 4
SP - 687
EP - 697
JO - ACS ES and T Water
JF - ACS ES and T Water
IS - 2
ER -