This research was conducted to investigate the acute toxicity spatial distribution in the sludge treating hydrophilic toxic pollutants N,N-Dimethylformamide (DMF) with various influent concentration (40 mg/L,80 mg/L,120 mg/L and 200 mg/L) in SBR process. The effect of treatment time on the values of effluent COD. concentration of DMF in water and sludge phases and organic toxicity in a single operation cycle were analyzed. The adsorption degradation contribution extent to formation of organic toxicity in un...