Abstract:Controlled indoor experiments were conducted to measure the excitation emission matrix spectroscopy (EEMs), SUVA254, TN, TP and DOC of both ice and water samples during the freeze-thaw process. The results showed an increase in the fluorescence intensity of tryptophan-like peak A, tyrosine-like peak B, and humic acid-like peak C in the aqueous phase during freezing. Additionally, the concentrations of TN and TP increased to 1.47 and 1.13 times the original water sample levels, indicating the migration of tryptophan-like, tyrosine-like and humic acid-like dissolved organic compounds, TN and TP from the ice phase to the aqueous phase due to the freeze concentration effect. As the volume of ice expanded, these substances migrated into the sediment and were released from the sediment into the water during the dissolution process. Correlation analysis results further showed that aromatic substances were more likely to migrate into the aqueous phase during freezing.