Efficient removal of dimethyl phthalate with activated iron-doped carbon aerogel through an integrated adsorption and electro-Fenton oxidation process

Abstract

A promising activated iron-doped carbon aerogel (AFeC) possessing high adsorption capacity and “self-cleaning” ability via generated OH radicals was fabricated and applied to remove dimethyl phthalate (DMP). Around 90% of the DMP (50 ppm) was first adsorbed on the surface of a DMP-imprinted AFeC electrode and then further catalytically oxidized by surface OH produced via an electro-Fenton reaction. DMP removal of 98% can be achieved in 150 min in the heterogeneous electro-Fenton process. The addition of Fe0 favoured the generation of graphene sheets of amorphous carbon and then provided strong π-π interaction with aromatic pollutants. In addition to iron, a DMP molecular template was also introduced to AFeC to create special molecular imprinting affinity for DMP. The CO2-N2 activation treatment increased the porosity and enriched the hydroxyl and quinone groups (C-O and C=O). The high DMP adsorption capacity of the DMP-imprinted AFeC electrode can be ascribed to the following mechanism: (i) electrostatic interaction; (ii) hydrophobic interaction; (iii) π-π electron-donor-acceptor interactions; (iv) molecular imprinting affinity between template molecules and imprinted sites. Thus, this carbon-based material is promising to be potentially applied in the removal of DMP containing wastewater through integrated adsorption and degradation.