In this study, we develop a facile ion exchange strategy for in-situ assembly of novel spherical metal-organic composites on a large scale. The functional groups (-NH2,-COOH and -SO3H) on chelating and exchange resins had significant effects on improving uniform distribution of metallic sites and metal-support interaction. Without any addition of H2O2, Mn-based metal-organic composites realized the recovery of waste metallic ions and exhibited high activity for methylene blue (MB) electro-Fenton degradation (97.8% decoloration and 54.7% TOC removal) within 150 min under low current density (7.53 inA.cm(-2)) and 3.0-1 catalyst dosage. Analyses of performance on different active sites (Fe-II, Mn-II, Co-II, Ce-II and Cu-II) and supports clearly indicated that synergetic effect of Mn" and organic supports played crucial roles in electrochemical oxidation. Kinetic rate constant