抄録
This study was carried out to clarify the effects of bacterial adhesion on powdered activated carbon (PAC) on bacterial activity using nitrate reduction activity E. coli K-12. E. coli K-12 was incubated with or without PAC. Additional amount of PAC ranged from 300 to 5,000mg·l-1 at 7.75×107 cells·ml-1 or from 20 to 90mg·l-1 at 1.78×108 cells·ml-1 of E. coli K-12. The cells concentration was also changed from 2.23×107 to 1.58×108 cells·ml-1 at a constant concentration of PAC, 1,000mg·l-1. High specific nitrate reduction rate was observed in cultures with PAC than those without PAC. The specific nitrate reduction rate increased with the increase in the ratio of adhered cells to total cells. The relationship between the specific nitrate reduction rate and the ratio of adhered cells to total cells was expressed by first order proportional equation. The results indicate that the adhesion of bacteria on activated carbon stimulates bacterial activity. The stimulation of bacterial activity did not result in adsorption of substrate, products or oxygen on PAC, therefore, it must depend on the interaction between adhered bacteria and the surface property of PAC.
