Abstract
Two species of algae, namely Microcystis aeruginosa which is a dominant species in eutrophic lakes and Nitzschia palea which mainly appears in urban rivers were cultivated in our laboratory. The relationship between the organic substances produced during the growing process and the concentration of trihalomethane produced by their chlorination was investigated. Furthermore, by gel chromatography, the organics were fractionated to elucidate the property of the component and the variation of trihalomethane formation potential during the growing process.
It is concluded that, in the case of Microcystis aeruginosa, total organic carbon is increased by the increase of degraded products during the death phase and those products form a high amount of trihalomethane by chlorination. Besides. some organics, whose trihalomethane formation potential is high, are excreted during the exponential phase.
The result of gel chromatography shows that the composition of soluble organics in the culture medium changes depending on the growth phase of algae.
And it is concluded that the formation of trihalomethane depends on the amount of organic which molecular weight is larger than 2, 000 and also possesses UV absorbance at 260 nm.
