Changes in Nitrogen Form in Paper Mill Wastewater Treated by Ozone Oxidation.

Ozonizers will produce nitrogen oxides which can be dissolved into the wastewater as ozone is produced. This experiment, where ozonization process was employed as the post-treatment after the biological processes, aims to analyze the amount of nitrogen and its variation and transform rate in influents and effluents. Results showed that after ozonization process, the concentrations of total nitrogen in effluents were higher than the concentrations in influents (0.01~0.38 times higher). The concentrations of nitrate nitrogen in effluents were also higher than the concentrations in influents, and average increased rate of NO₃-N was 226.8%. Furthermore, the increase in the concentration of NO₃-N due to dissolution of NO_x was 47.10% of total increase in NO₃-N. [ABSTRACT FROM AUTHOR]