The decrease in pH and the increase in conductivity
obtained are consistent with degradation of the large surfactant
molecules into smaller fragments. However, the
effect of NaOH on the surfactant degradation is not
straightforward. With respect to COD there is a trend
towards an increase in COD reduction. The powerful
ozone ? medium-pressure UV treatment becomes even
more effective in the presence of alkali. The situation is
different when it comes to TOC reduction