LAUSR

In this study, a lab‐scale sequencing batch bioreactor (SBR) with hydraulic retention time (HRT) of 8 h was established to treat 50 mg/L 4‐chlorophenol (4‐CP), and the temporal responses of 4‐CP on the performance and the expression level of related functional genes in sludge were explored. Results showed that after the SBR was acclimated with the cometabolic carbon sources of 4‐CP and methanol, the pollutants were effectively degraded. The pollutants removal was influenced by the polysaccharides and proteins in sludge. The real‐time PCR showed that except for the gene p450, the prompt removal of pollutants before 2 h caused the significant upregulation of the other functional genes from the genus Pseudomonas in sludge, while the downregulation occurred from 2 to 8 h with the progressive removal of pollutants in SBR cycle, indicating that the removal of pollutants was closely related to the functional genes expression.