Enhanced anaerobic degradation of quinoline, pyriding, and indole with polyurethane (PU), Fe3O4@PU, powdered activated carbon (PAC), Fe(OH)3@PAC, biochar, and Fe(OH)3@biochar and analysis of microbial succession in different reactors

Abstract The study was to explore the feasibility of polyurethane (PU), Fe3O4@PU, powdered activated carbon (PAC), Fe(OH)3@PAC, biochar, and Fe(OH)3@biochar as biological carriers in strengthening anaerobic degradation of quinoline, pyridine, and indole. When the concentrations of pollutants were 25 mg/L and 50 mg/L, reactors based on PAC and Fe(OH)3@PAC had higher degradation ratios than the other reactors. However, when the concentrations of pollutants were 75 mg/L and 100 mg/L, with the addition of PU and Fe3O4@PU, reactors began to show their superiority in the degradation of the selected NHCs. Among these, the reactor based on Fe3O4@PU had the optimal degradation ratio on quinoline, pyridine, and indole. PU, PAC, Fe(OH)3@PAC, biochar, and Fe(OH)3@biochar benefited the enrichment of Acinetobacter, Comamonas, Levilinea, Longilinea, and Desulfomicrobium. The reactor with the carrier of Fe3O4@PU had some specificity, which benefited the enrichment of Zoogloea, Thiobacillus, Anaeromyxobacter, Sphingobium, Terrimonas, Parcubacteria genera incertae sedis, Bdellovibrio, Rhizobium, and Acidovorax.