Electrochemical sterilization of bacteria absorbed on granular activated carbon

The electrochemical sterilization of bacteria adsorbed on granular activated carbon (GAC) was demonstrated. The survival ratio of bacteria on GAC was dependent upon the applied potential. The survival ratio of Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Saccharomyces cerevisiae vs. saturated calomel electrode (SCE) was below 1% at 0.75, 0.8, 1.0 and 0.65 V, respectively. The electrochemical sterilization of tap water containing E. coli was carried out when 3.5 ml of the cell suspension (4.0 x 10(2) cells/ml) was incubated with 2.0 g of GAC for 5 h at 0.7 V vs. SCE. The number of E. coli adsorbed on GAC and the cell concentration in the water decreased rapidly. E. coli on GAC were electrochemically killed and the cell numbers did not increase.