In general, colour reduction has been shown to coincide with changes in molecular
structure (aromatic to aliphatic) or degradation of organic macromolecules into smaller molecules leading to partial mineralisation [8,23]. These low molecular weight (LMW) breakdown products are more readily biodegradable as they act as a major food source for
microbes [10,24], thus integration of AOPs with downstream biological treatment can significantly improve the removal of organic carbon [9,12].