Non-radical pathway dominated by singlet oxygen under high salinity condition towards efficient degradation of organic pollutants and inhibition of AOX formation

• 3D N-doped graphene aerogel supported on nickel foam (NGA@NF) was fabricated. • NGA@NF could dramatically reduce AOX formation in high salinity wastewater. • Efficient mineralization of AO7 was achieved under high salinity conditions. • 1 O 2 was elucidated as the primary reactive oxygen species in NGA@NF/PMS system. • NGA@NF possessed good mechanical strength and regeneration performance. It is still a challenge to effectively treat organic pollutants and control the formation of adsorbable organic halogens (AOX) under high salinity owing to the inevitable side reactions among chloride ions and reactive radicals. Herein, 3D N-doped graphene aerogel supported on nickel foam (NGA@NF) was designed for non-radical pathway through peroxymonosulfate (PMS) activation. The NGA@NF exhibits excellent catalytic activity with 92% removal of acid orange 7 (AO7) within 10 min under high salinity environment ([Cl - ] 0 = 200 mM), owing to the synergistic effects of 3D hierarchy porous structure and high nitrogen doping level (6.8%). Due to the superb resistance of singlet oxygen ( 1 O 2 ) to radical scavengers (Cl - ), 78% of the total organic carbon (TOC) was removed in NGA@NF/PMS system, which is much higher than the traditional Co 2+ /PMS system (3%). Importantly, AOX value in NGA@NF/PMS system was 6.5 times lower than that in Co 2+ /PMS system. Kinetic calculation indicates that the effective inhibition of AOX formation could be attributed to the non-radical pathway with 1 O 2 as primary reactive species. This work highlights leveraging the non-radical pathway dominated by 1 O 2 to environmental remediation under high salinity conditions by a promising material.