Enhanced VOCs catalytic degradation through AOP wet scrubbing with sludge-derived carbon loaded Co-Fe alloy.

Advanced oxidation process (AOP) coupled with wet scrubber is an efficient and environmental technology for the treatment of volatile organic compounds (VOCs) emitted from soil thermal desorption. Developing a cost-effective, high-performing and stable catalyst for the specific scenarios is still considered a challenge. In this work, a highly active sludge-derived carbon catalyst loaded with Co 3 Fe 7 bimetallic alloy (DSHC(Fe)-Co) was elaborately designed for efficient PMS activation to achieve the deep oxidation of these toxic VOCs in AOP wet scrubber. The removal efficiency of the typical VOCs, gaseous benzene, remained above 99 % over a wide pH range from 3 to 11, which was better than that of the single Fe or Co catalyst. In addition, the system also demonstrated superior degradation performance higher than 98 % for other pollutants (toluene, xylene, ethyl acetate and cyclohexanone). A series of experiments and characterizations indicated that the free radical pathway, dominated by SO 4 •^- and •OH, resulted in the outstanding removal performance of DSHC(Fe)-Co, which was attributed to the synergistic interaction between Fe and Co species. This study presents a novel method for sludge resource utilization and facilitates the application of AOP wet scrubbing technology in the treatment of VOCs. [Display omitted] • A sludge-derived carbon loaded with Co 3 Fe 7 alloy was synthesized. • Catalyst fabricated by a hydrothermal process was more stable due to lower ion leaching. • Hydroxyl radicals and sulfate radicals contributed to benzene degradation. • Bimetallic synergy between Fe and Co enhanced the activation capacity. [ABSTRACT FROM AUTHOR]