New insight into the role of FDOM in heavy metal leaching behavior from MSWI bottom ash during accelerated weathering using fluorescence EEM-PARAFAC

•FDOM components and their changes of IBA were identified by EEM-PARAFAC.•Accelerated weathering process can be divided into three phases based on FDOM analysis.•Adsorption of humic-like onto neo-formed reactive surfaces concluded quickly.•HPI fraction biodegradation plays a vital role in Cu and Cr leaching after carbonation.•A novel method for improving accelerated weathering of IBA is proposed.