炭素繊維電極への微生物の電気的吸着に及ぼすシリカの影響

抄録

We have considered a method to collect and sterilize bacteria using a positively-charged carbon fiber electrode. The feature of this method is that it can sterilize spores, which could not be sterilized by heating or bactericidal agents. However, the capacity to collect Bacillus subtilis spores decreased in the silica solution. To investigate this matter, we measured the effective surface area and bacteria affinity of the carbon fiber dipped in 100 ppm silica solution for 24 hr, and investigated the method to improve the collecting capacity. The results were as follows. The surface coverage of silica was 57%, calculated from the weight change, or 53%, calculated from the electrolytic current change. The zeta potential of the carbon fiber decreased from −11 mV to −15 mV, and Bacillus subtilis spores were not adsorbed into the carbon fiber on their own. When a constant cathodic current of 1 A was applied to the carbon fiber, the capacity to collect the Bacillus subtilis spores increased from 88.05% to 99.88%, and the surface coverage of silica was about 5%. Therefore, it was considered that silica was dissolved in water, and the capacity to collect bacteria could be recovered.