Low-Cost ceramic disk filters coated with Graphitic carbon nitride (g-C3N4) for drinking water disinfection and purification

Access to safe drinking water is a challenge in remote and rural areas, where thus urgently need cost-effective household drinking water purification device. In this study, a ceramic disk filter coated with modified g-C3N4 (MCN@CDF) was developed for drinking water disinfection and purification. Factorial analysis results showed that factors including the coating amount of MCN, light intensity, influent humic acid (HA) concentration, influent turbidity, and influent pH had significant positive effects on the E. coli removal efficiency of MCN@CDF. However, the influent turbidity had a significant negative effect on the permeability. The significant 2-factor interaction effects on the performance of MCN@CDF were also discussed. The developed MCN@CDF showed an exceptional performance in bacterial removal, and the log reduction value (LRV) could reach up to 7.14. This could be ascribed to the synergistic effect of physical retention and photocatalytic disinfection. The photocatalytic disinfection was induced by MCN under light irradiation, which produced H2O2 and h+ to inactivate E. coli. These reactive species could attack E. coli cells, causing changes in the cell shape and damage to DNA. The developed MCN@CDF also exhibited excellent practicability during treating realistic ground water, which met the standard of drinking water after purification with MCN@CDF. This study provided a low-cost and safe alternative for household drinking water purification in rural areas.