Cost-Effective H2O2-Regeneration of Powdered Activated Carbon by Isolated Fe Sites

Abstract

The reuse of powdered activated carbon (PAC) vitally determines the economics and security of the PAC-based adsorption process, while state-of-the-art PAC regeneration technologies are usually unsatisfactory. Here, it is demonstrated that isolated Fe sites anchored on commercial PAC enable fast H2O2 activation to produce Fe-based reactive oxygen species for highly efficient PAC regeneration at room temperature. Taking rhodamine B as a representative pollutant, PAC decorated with isolated Fe sites realize H2O2 based regeneration with negligible adsorption capacity degradation for 10 cycles. Moreover, in terms of the PAC loss rate, this technology is greatly superior to traditional Fenton-based regeneration technology. Further operando experiments and theoretical calculations reveal that the high regeneration performance can be attributed to the isolated HO-Fe-O motifs, which activate H2O2 via a nonradical reaction pathway. These findings provide a very promising strategy toward reducing the cost of H2O2-based PAC regeneration technology.