抄録
The influences of the transformations of dissolved organic matter (DOM) on the excitation-emission matrix (EEM) were investigated for the samples obtained from Hiroshima Bay, the rivers inflowing into the bay, sewage treatment plant, etc. and then subjected to photolysis and microbial degradation. We found that Peak6 of the EEM changed most markedly and that the difference in irradiation sources between sunlight and black light made negligible difference in EEM transformations. Distinct changes in EEM were not observed for the microbial degradation, except Peak4 for the samples characterized by prominent Peak4. The peak positions of EEM remained within ± 10nm through the transformation processes by photolysis or microbial degradation. The rate constants of RFI/DOC (relative fluorescence intensity divided by DOC) at Peak3, Peak4 and Peak6 exhibited positive values for photochemical degradation and on the other hand negative values for microbial degradation.
