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

Ozonizers will produce nitrogen oxides which can be dissolved into thewastewater as ozone is produced. This experiment, where ozonization process was employedas the post-treatment after the biological processes, aims to analyze the amountof nitrogen and its variation and transform rate in influents and effluents. Results showedthat after ozonization process, the concentrations of total nitrogen in effluents were higherthan the concentrations in influents (0.01~0.38 times higher). The concentrations ofnitrate nitrogen in effluents were also higher than the concentrations in influents, andaverage increased rate of NO3-N was 226.8%. Furthermore, the increase in the concentrationof NO3-N due to dissolution of NOx was 47.10% of total increase in NO3-N.