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In this study, three sequencing batch biofilter granular reactors (SBBGRs) were employed to treat model lignin wastewater containing different lignin models (2,6-dimethoxyphenol, 4-methoxyphenol, and vanillin). After 40 days of cultivation, uniform-shaped aerobic granular sludge (AGS) was successfully developed through nutrient supplementation with synthetic wastewater. During the acclimation stage, the chemical oxygen demand (COD) reduction efficiencies of the three reactors showed a trend of initial decreasing (5-20%) and then recovering to a high reduction efficiency (exceeding 90%) in a short period of time. During the stable operation stage, all three reactors achieved COD reduction efficiencies exceeding 90%. These findings indicated the cultivated AGS's robust resistance to changes in lignin models in water. UV-Vis spectra analysis confirmed the effective degradation of the three lignin models. Microbiological analysis showed that Proteobacteria and Bacteroidetes were always the dominant phyla. At the genus level, while Acinetobacter (15.46%) dominated in the inoculation sludge, Kapabacteriales (7.93%), SBR1031 (11.77%), and Chlorobium (25.37%) were dominant in the three reactors (for 2,6-dimethoxyphenol, 4-methoxyphenol, and vanillin) after degradation, respectively. These findings demonstrate that AGS cultured with SBBGR effectively degrades lignin models, with different dominant strains observed for various lignin models., Competing Interests: The authors declare there is no conflict., (© 2024 The Authors This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 4.0), which permits copying, adaptation and redistribution, provided the original work is properly cited (http://creativecommons.org/licenses/by/4.0/).)

Advanced oxidation technologies based on hydroxyl radical (•OH) and sulfate radical (SO 4 -• ) are two common types of advanced oxidation technologies, but there are not many reports on the application of advanced oxidation methods in actual wastewater pretreatment. This article compares the pre-treatment performance of Fe 2+ /H 2 O 2 and Fe 2+ /Persulfate systems in actual pharmaceutical wastewater, and combines EEM, GC-MS, and toxicity testing results to explore the differences in TOC, COD, and NH 3 -N removal rates, optimal catalyst dosage, applicable pH range, toxicity of effluent after reaction, and pollutant structure between the two systems. The results indicate that the Fe 2+ /H 2 O 2 system has a higher pollutant removal rate (TOC: 71.9%, COD: 66.9%, NH 3 -N: 34.1%), but also requires a higher catalyst (Fe 2+ ) concentration (6.0 g/L), and its effluent exhibits characteristic peaks of aromatic proteins. The Fe 2+ /Persulfate system has a wider pH range (pH ≈ 3-7) and is more advantageous in treating wastewater containing more cyclic organic compounds, but the effluent contains some sulfur-containing compounds. In addition, toxicity tests have shown that the toxicity reduction effect of the Fe 2+ /Persulfate system is stronger than that of the Fe 2+ /H 2 O 2 system.