Melamine enhancing Cu-Fenton reaction for degradation of anthracyclines

Melamine (MA) enhanced Cu-Fenton process was developed for the degradation of anthracyclines. Taking daunorubicin (DNR) degradation as an example, we found that the initial first-order apparent constant of Cu 2+ /MA/H 2 O 2 system with a molar ratio of 1:8 for Cu 2+ :MA was 5.2 times higher than that of conventional Cu 2+ /H 2 O 2 system. The in-situ reductive coordination between Cu 2+ and MA facilitated the generation and stabilization of Cu + species, thereby accelerating the rate-limiting step of Cu 2+ /Cu + conversion and maintaining high levels of Cu + during the degradation process. Moreover, pre-synthesized Cu + -MA complexes ( e.g. , CM-250) further enhanced the efficiency of the Cu-Fenton reaction by increasing both the Cu + proportion and MA chelation. The apparent activation energy for DNR degradation in CM-250 mediated Fenton reaction (15.9 kJ mol −1 ) was lower than that in systems involving Cu 2+ /MA (41.2 kJ mol −1 ) and Cu 2+ (65.6 kJ mol −1 ). Enhanced generation of various reactive oxygen species (·OH,·O 2 - , and 1 O 2 ) was confirmed, with 1 O 2 playing a dominant role, significantly improving both degradation rate and mineralization degree for DNR. MA-enhanced Cu-Fenton process also offers a convenient alternative to effectively remove other anthracyclines and organic micropollutants, holding great promise for advancing advanced oxidation processes as well as practical large-scale degradation applications targeting multiple pollutants.