Abstract
The formaldehyde concentration of a dilute solution prepared with deionized water, which is frequently used in laboratories, decreased rapidly in a few days and formaldehyde disappeared within about 2 weeks at room temperature. When the solution was prepared with river water, the decreasing rate of formaldehyde in the solution was markedly accelerated. The solution was stabilized by using steamsterilied water or by the addition of chloroform, cupric ion (10 ppm), or mercuric ion (10 ppm). The solution was also stable in acidic medium of below pH 2 or alkaline medium of above pH 12. From these experimental results, it was ascertained that the decrease of formaldehyde was due to its decomposition by microbes.
