The humic acid-like peak disappeared before the fulvic acid-like peak, as clearly shown for UVC irradiation (Fig. S3, Supplementary information).
The EEMs for VUV-irradiated samples displayed a similar trend but at a higher rate, with almost complete removal of fluorescent matter after 180 min. The addition of hydrogen peroxide greatly increased the rate of disappearance, such that complete
removal of the peaks was observed after 120 min.