Evaluation of the biocidal effects of activated carbon filter supporting silver

The objectives of this study are to investigate the relationship between the silver ion concentrations released from the point-of-use(POU) water purification devices installed silver impregnated activated carbon filters and the antibacterial activities against HPC bacteria. Total of 68 POU devices were tested. The concentrations of the eluted silver ion from the silver impregnated activated carbon filter showed the range from $4\;{\mu}g/L$ to $386\;{\mu}g/L$, and the HPC bacteria were found to diversely grow within the range 0-5,200 cfu/mL. The average silver concentrations released from UF units system and RO units system were $30\;{\mu}g/L$ and $73\;{\mu}g/L$, respectively. And the number of colonies were reduced significantly as the elution levels of silver exceeded $100\;{\mu}g/L$, however silver ions below the concentration of $100\;{\mu}g/L$ were not particularly effective for eradicating HPC bacteria from water.