Ozonation characteristics of dissolved effluent organic matter from the secondary effluent of WWTP

HPLC-SEC coupled with a fluorescence detector was combined with an EEM spectra to study the ozonation characteristics of EfOM. The findings showed that ozonation did not change the molecular weight distribution of the humic-like substances. Furthermore, the HPLC-SEC results indicated that the molecular weight distribution of the humic-like substances was not changed by ozonation. Nonetheless, ozone reacted with the low molecular weight protein-like substances. According to preparative HPLC analysis, the low molecular weight protein-like substances contained large amounts of aromatic or other conjugated structures, which were preferentially ozonated. In addition, XPS analysis revealed that the aromatic structure was oxidized at a low ozone dosage, and the amount of aliphatic organic matter increased correspondingly. With the increasing of ozone dosage, the amount of oxygen-containing functional groups (carbonyl and carboxyl group) increased.