Adsorption and in-situ photocatalytic Fenton multifield coupled degradation of organic pollutants and coking wastewater via Fe BiOBr modification of three-dimensional graphene aerogel

Both adsorption and advanced oxidation processes can achieve rapid removal of organic pollutants. Based on this, FeBiOBr was modified on the surface of three-dimensional graphene aerogel (3D rGA) to construct FeBiOBr/rGA composites. Using the surface adsorption properties of graphene to quickly adsorb pollutants, combined with photocatalytic Fenton degradation by FeBiOBr catalysts, the adsorption and in-situ photocatalytic Fenton multifield coupled degradation system was constructed by the consistency of adsorption and catalytic degradation sites. Experimental results showed that FeBiOBr/rGA has a 2.92-fold increase in the adsorption capacity for phenol compared with bulk rGA. Meanwhile, the degradation rate constant was 2.7 times higher than that of FeBiOBr because of the excellent electrical conductivity of graphene. In addition, it also exhibited excellent COD and TOC removal performance for different phenolic and coking wastewaters. The effects of graphene content, catalyst dosage, H2O2 concentration and other factors on the adsorption-catalytic degradation activity of the synergistic system were further investigated. Based on the influence of active species, the mechanism of FeBiOBr/rGA composite adsorption and in-situ catalytic degradation multifield coupling removal of pollutants was proposed. In addition, the 3D rGA could effectively solve the problem of difficult recycling of powder catalysts and has significant practical application potential.