Enhanced ferrate decontamination efficiency by acetylene black: The role of ketonic groups as electron-donating sites

carbonaceous materials (CMs) have attracted broad concern as catalysts in wastewater remediation due to their excellent physicochemical and structural properties. Here, the decontamination ability of ferrate (Fe(VI)) was evaluated in the presence of various CMs and Fe(IV)/Fe(V) was determined as predominant species. Acetylene black (AB), a kind of carbon black widely used in the modification of electrode materials, showed the best activation effect on Fe(VI) decontamination. Ozone pre-oxidation combined with characterization analyses revealed the critical role of ketonic (C--O) groups on AB as reductive sites. The promoting effect of Fe(III) and H2O2 indicated the involvement of Fe(VI) decay products in the activation process. Additionally, the decontamination efficiency above 90% in cyclic tests and actual waters reflected the advantages of nonradical oxidation in the heterogeneous Fe(VI)-AB system, indicating its great potential in practical application for wastewater remediation.