Genotoxicity removal of reclaimed water during ozonation.

Genotoxicity in wastewater and reclaimed water now is gaining increased attention because of genotoxins' potential damage to the ecosystem and human health. The effect of ozonation on genotoxicity in reclaimed water was investigated. It was found that ozonation decreased the genotoxicy dramatically in three tertiary treatment plants. In the further batch ozonation experiment in laboratory, secondary effluent sample used exhibited the genotoxicity of (41.1 ± 4.1) μg 4NQO/L. Ozonation with a dose of 10 mg O3/L completely removed the genotoxicity in secondary effluent. However, after ozonation, the dissolved organic carbon value of the sample didn't change much but the specific ultraviolet absorbance (SUVA) value dropped sharply. With the help of Fourier transform infrared spectroscopy, ozonation was found to change chemical aliphatic carbon and C-O of the dissolved organic matter, which might be the reason of the significant decreases of SUVA and genotoxicity.