Suchergebnisse

AbstractDue to the higher uncertainty of environmental risk for pollutants' treatment by activated sludge, 10 mg/L influent 4‐chlorophenol (4‐CP) treated via a sequencing batch reactor (SBR) was used as acclimated SBR. Another SBR was used as control SBR without 4‐CP. The effects of hydraulic retention time (HRT) and proteins on sludge toxicity for 4‐CP treatment were analysed, and compared to the control SBR. Results showed that the sludge toxicity in acclimated SBR was significantly higher than that of the control SBR. Shortening HRT from 12 to 8 hours was beneficial to degrade 4‐CP and lower sludge toxicity. The identified highly expressed protein of ABC transporter co‐existed in control and acclimated SBRs, while other proteins of TonB‐dependent receptor, heat shock 70 kDa protein and superoxide dismutase in acclimated sludge were overexpressed relative to the control sludge, which played an important function in degrading 4‐CP, resisting 4‐CP toxicity and eliminating sludge toxicity.

AbstractIn 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.