抄録
Some batch ozonation experiments on the secondary effluents. The identification of intermediates and end products resulting from the ozonation was studied, setting the reaction time and the ozone concentrations applied as reaction parameters. The feed gas to the reactor had ozone concentration of 9.6-59.5 mg/l.
Trace amounts of formaldehyde, acetaldehyde, proponic aldehyde, methyglyoxal, glyoxylic acid and pyruvic acid were detected by gas chromatography and colorimetry for 2, 4-dinitrophenylhydrazones. Formaldehyde was a common product resulting from the ozonation of many organic compounds in the early reaction time. But, this was finally oxidized to carbon dioxide by the prolonged reaction time at a faster rate. Methylglyoxal and pyruvic acid were also oxidized to pyruvic acid and acetic acid, respectively. But, the decomposition rate of pyruvic acid is not so fast as formaldehyde's.
Acetic acid, formic acid and propionic acid were also detected by gas chromatography for their benzyl esters. The latter two were present in trace amounts. The quantity of acetic acid increased with the reaction time increment.
During the course of the reaction, 1/6-1/5 of total COD can be accounted for by the summations of each TOD on formaldehyde, methylglyoxal, pyruvic acid and acetic acid produced by the ozonation of secondary effluents.
