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

Abstract

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.

Low-Cost Antibacterial Ceramic Water Filters for Decentralized Water Treatment: Advances and Practical Applications

“…However, in the case of CPWF with Eragrostis tef husk, some residues may persist despite the combustion process . The research findings, comparing combustible materials such as sawdust, maize cob, and cassava, revealed that sawdust produced the most optimal porosity . As a result, they achieved the highest flow rate of filtered water.…”

“… 45 The research findings, comparing combustible materials such as sawdust, maize cob, and cassava, revealed that sawdust produced the most optimal porosity. 49 As a result, they achieved the highest flow rate of filtered water. The high porosity of the filter plays a crucial role, as it allows water to pass through easily while efficiently removing impurities.…”

“…A ceramic water filter modified with Ag nanoparticles also demonstrates excellent antibacterial properties. The experimental results indicate that the ceramic water filter with Ag nanoparticles can increase the bacteria removal from 99% (without Ag nanoparticles) to 100% . The mechanism of bacterial elimination may be related to the synergistic effect between filtration and disinfection with AgNPs .…”

“… Introduction of silver nanoparticles into the CWF. (a) Ag nanoparticles impregnation (reprinted from ref ( 49 ). Copyright 2023, The Authors.…”

“…The impregnation method has been utilized for the modification of ceramic water filters with silver nanoparticles, as described in ref ( 49 ). To initiate the impregnation process, the ceramic water filter is first activated using a hot piranha solution (1:3 v/v, 30% H 2 O 2 /98% H 2 SO 4 ).…”