pH indications in aqueous organic photodecompositions with carbonyl and hydroxyl groups

A pH variation pattern during organic compound (ethylene glycol, phenol, and glucose) decomposition under UV/H2O2 of different schemes was observed. This method was successfully applied to reflect the organic carbon oxidation progress, especially the rapid chemical oxygen demand (COD) decrease timing in the later mineralization stage. The results were demonstrated in a sequential feed-batch advanced oxidation reactor, showing that pH can be used as an alternative indicator to provide complete oxidation and cycle time information.