Killing Two Birds with One Stone: Coating Ag NPs Embedded Filter Paper with Chitosan for Better and Durable Point-of-Use Water Disinfection

Abstract

In this study, porous chitosan (CS) coated Ag NPs embedded filter paper (CAEFP) was fabricated for point-of-use water disinfection application. Thanks for the presence of CS coating, the tensile strength of the CAEFP in wet condition was found to be 1.8 MPa, 700% increase compared with where there was no CS coating, making it much more durable. In addition, the coating with CS could greatly boost the Ag NPs loading without worrying about the excessive release of Ag into the treated water, thereby significantly improving the bactericidal efficiency but still be safe to drink in terms of Ag release. Furthermore, by controlling the amount of CS used, the flow rate and bactericidal efficiency of the CAEFP could be manipulated (customized). When the CS content increased from 0.5 to 2.0 wt %, the flow rate of CAEFP would drop from 9.3 to 0.53 L/min/m2, and the bactericidal efficiency against Escherichia coli and Bacillus subtilis could improve from 4 and 3.6 to 4.9 and 4.8 log reduction, respectively. At optimum condition, the total Ag in treated water by CAEFP was below 45 μg/L, only 1/10 of that from Ag NPs loaded filter paper without CS coating, half of the WHO drinking water requirement (<100 μg/L). Natural surface water samples were used for the demonstration of the bactericidal performance of the CAEFP. Both the total bacterial and E. coli counts met the WHO standard.

N-Doped Carbon-Coated Cu7S4 Nanowires on Cu Foam Supports for Water Disinfection

“…Water is the source of life, and the safety of drinking water is closely related to people’s health. , The biological pollution of bacteria, viruses, and parasites will cause infectious diseases such as typhoid fever, cholera, and hepatitis A, , which seriously endanger human lives. How to obtain sufficient drinking water quickly and steadily has always been the focus of people’s attention.…”

Silver Nanoparticle-Incorporated Porous Renewable Film as Low-Cost Bactericidal and Antifouling Filter for Point-of-Use Water Disinfection

“…Therefore, effective point-of-use (POU) technologies are urgently needed to reduce the percentage of pathogens in water supply before use. 2,5,6 In the past decade, numerous technologies have been developed and applied in POU processing systems. Among them, membrane filtration which can remove a wide variety of contaminants in drinking water is currently one of the most mature and effective POU water purification technology aiming to prevent waterborne disease.…”

Robust immobilization of anionic silver nanoparticles on cellulose filter paper toward a low-cost point-of-use water disinfection system with improved anti-biofouling properties

“…With the increase of permeate volume to 2 L, the silver concentration gradually decreased to 24 μg L −1 , which meets the US EPA guideline for drinking water (<100 ppb), demonstrating the safety of GA@AgNPs-LA-FP for water disinfection. 14 To prove the non-toxicity of the released Ag + ions, the solution containing released Ag + ions was further used to culture fibroblast L929 cells to test for in vitro cytotoxicity. As shown in Fig.…”

“…Although some of the bacteria in raw water were physically removed by FP, the quality of the filtered water was not up to the standard for drinking water (total bacteria < 100 CFU mL −1 , no coliforms). 14 …”