In-situ Cu-doped carbon-supported catalysts applied for high-salinity polycarbonate plant wastewater treatment and a coupling application

Abstract Organic pollutants decomposition in high-salinity wastewater is still a challenge for environmental restoration due to the inhibitory effects results from the consumption of radicals by anions. Herein, we demonstrated a non-radical oxidation process via the peroxydisulfate (PDS) activation rather than photocatalysis by the Cu2+ adsorbed adsorbent-based nitrogen doped biochar (Cu@NBC) for efficiently decontaminating polycarbonate plant wastewater (PCW). After the pyrolysis, the Cu2+ in the waste biosorbent were reduced to Cu2O, and the N-doping improved the fixation of Cu and the formation of Cu2O. Through both dynamic fitting and characterization analysis, the critical role of Cu2O in PDS activation rather than photocatalysis was revealed for the first time. Different from always reported 1O2 dominated non-radical process, an electron-transfer mechanism involving surface metastable species was proved to play a key role in the Cu@NBC/PDS system. Benefit from the electron-transfer process, the Cu@NBC/PDS system equipped with high resistance to the anions in high-salinity wastewater. The results indicated that BPA as well as chemical oxygen demand (COD) could be effective removal within 90 min. We further deposited the activator on an ultrafiltration membrane and exhibited a rapid oxidation of BPA as the wastewater passed through the filter, and the composite membrane can effectively inactivate bacteria, which will provide a safety strategy for mitigation of membrane fouling.