Water disinfection using durable ceramic filter coated with silver nanoparticles synthesized using actinomycetes

Contamination with pathogens degrades water quality and is a major cause of many waterborne diseases. The aim of this research is to reduce the global disease burden by presenting an efficient, durable, and low-cost ceramic filter impregnated with actinomycetes-mediated silver nanoparticles (AgNPs) for water disinfection in rural areas. This marks the first report on the simultaneous biosynthesis of AgNPs utilizing cell-free supernatants obtained from terrestrial actinomycetes. An easy and efficient method was used to impregnate AgNPs onto a ceramic filter using 3-aminopropyltriethoxysilane (APTES). The APTES linker is anchored to the ceramic surface through Si–O–Si bridges, while the terminal amino groups coordinate with AgNPs. Notably, the observed inhibition zone around the filter with AgNPs was ~ 18 mm, suggesting that the silver ions were responsible for the antibacterial activity. After 30 min of sonication, only insignificant traces of AgNPs were released from the filter, making it stable for long-term antibacterial activity when treating water. According to the laboratory simulation experiments, the untreated filter can reject about 99% of spiked bacteria, while the antibacterial efficiency of the filter coated with AgNPs was 100% due to the synergistic effect between filtration and disinfection with AgNPs. In addition, the average concentration of dissolved silver in the outlet water of the ultrafiltration system during three months was 33.7 μg/L, far below the permissible limit (100 μg/L) for drinking water. Overall, this work offers a suitable and affordable water treatment strategy for low-income, isolated, and rural societies in developing countries.