殺菌燈による水の消毒
1952 年 36 巻 3 号 p. 89-96
詳細
1952 年 36 巻 3 号 p. 89-96
1. In the preliminary experiment, useing a newly developed 15-W germicidal lamp, we ascertained the lethal exposure necessary to kill various organisms, such as non-spore formers (Bacillus coli, Eberthella typhosa, Shigella dysenteriae, Staphylococcus aureus, etc.), spore formers (Bacillus subtilis Bacillus mesentericus and their spores), and various species of yeast.
Much greater exposures are necessary to kill the spore forming bacteria and yeast than pathogenic enteric organisms.
2. In the disinfecting experiment of well-water, using a trial set of disinfecting water tank and highly polluted water with B. coli for fundamental investigations, we obtained the foIlowing results.
a. 8 liters of water was completely disinfected within 45 seconds in case of still water.
b. From 2 to 4 liters per minute of water was completely disinfected and 99.9% of test organisms in 5 liters were killed in case of running water.
3. It should be emphasized the rate of disinfection of water varies not only with the organisms but also with the nature of water, especially the absorption coefficient of ultraviolet light in the region of λ 2537.
4. The relations among the degree of killing or survival ratio, the volume or running speed of water and absorption coefficient were calculated, and compared with the experimental results. The formulae are useful for the design of the actual disinfection apparatus of water.
