Non-metallic hollow porous sphere loaded CN/catalytic ozonation synergistic photocatalytic system: Enhanced treatment of emerging pollutants by three-stage cyclic reaction mechanism

Against the backdrop of carbon abatement, exploring a clean, efficient, low cost and flexible system to treat emerging pollutants has attracted more and more attention. Non-metallic hollow porous sphere (HSCHy) based on improved hydrothermal Enteromorpha prolifera biochar and modified diatomite loaded CN (HSCHy-CN) was prepared and applied to catalytic ozonation synergistic photocatalytic (HSCHy-CN/COP) system. HSCHy-CN had strong interaction with pollutions and stable p-p junction with O3. EbCHy in HSCHy-CN can effectively transfer e-. These can promote mass transfer of active components. And then·O2--centered three-stage cyclic reaction, which is dominated by transient mass transfer, electrophilic/nucleophilic attack and mineralization occurs. The degradation rate of tetracycline (TC) and p-nitrophenol (PNP) in 20 min was 90.1% and 84.3%, respectively. The good treatment effect of HSCHy-CN/COP system on secondary effluent and oilfield produced water also proved its potential as advanced treatment and pretreatment of secondary treatment. [Display omitted] •HSCHy-CN with good COP catalytic activity and stability is prepared.•HSCHy-CN/COP system is efficient for the degradation of emerging pollutants.•HSCHy-CN/COP system obeys a·O2--centered three-stage cyclic reaction mechanism.•HSCHy-CN/COP system exhibits excellent activity for the removal of actual wastewater: OW and SW.