The preservation of water quality and natural environment is increasingly important among the industrialized society. Effluent discharge standards employed by Environment Agency, Japan Federal Government have prevented rivers, lakes, and oceans from the pollution by human activities. The number of novel man-made hazardous substances produced by industries is increasing according to the year, resulted in conventional discharge standards ineffective to preserve natural ecological environment. A novel monitoring parameters to detect unknown pollutants sensitively are need to be investigated.
In this study, the population change in the benthic fauna was used to monitor environmental effect of disinfection agent on rivers. Two separate streams of treated sewage are compared by this method. One stream is treated by chlorine for the disinfection, and ozone treatment were employed for the other stream.
The stream disinfected by chlorine changed benthic fauna drastically compared to that by ozone. The population diversity of the benthic fauna in the river receiving the ozone treated stream was larger than that in the river receiving the chlorinated stream. In conclusion, ozone treatment found to be more effective to preserve the natural ecological environment of the river.
