Direct Photolysis

Along with initiating reactions via OH radicals (generated from H2O2) the direct photolysis of water ingredients by UV irradiation plays a major part. However, sufficient absorption of these substances is required, which can then selectively be destroyed under proper process conditions. Especially the possibility of a selective oxidation of toxic ingredients is a major advantage with respect to costs and efficiency.  

Examples for direct photolysis of contaminants or pollutants:
EDTA (Ethylendiamintetraacetic acid)

 

This reaction initiates the transformation of the virtually non-biodegradable EDTA to the good biodegradable NTA, which is degradable in the biological phase of the sewage treatment plant.

With an additional oxidation cycle, the EDTA also becomes completely mineralizable. 

DMSO (Dimethyl sulfoxide)

 

NDMA (N-Nitrosodimethylamine)

 

DMSO and NDMA are directly destroyed under UV irradiation and further oxidized in the subsequent reactions.