Impact of 4-nitrophenol on minimization of excess sludge production and performance of sludge in activated sludge process
4-硝基酚的污泥减量化作用及对污泥性质的影响

Reduction of excess sludge production in activated sludge process was investigated by utilizing uncouplers,4-nitrophenol.The effects of 4-nitrophenol on the growth rate of the sludge,substrate removal and sludge properties were further examined.The experimental data show that the sludge production could be reduced effectively by 4-nitrophenol,but only slight reduction in COD removal was obtained.After addition of 4-nitrophenol,the effluent TN and TP concentrations increased slightly,but the effluent NH4+-N concentration almost maintained a constant value.4-nitrophenol improved bioactivity of biomass and increased the oxygen consumption rate of biomass resulting in promoting energy decouple league,which can reduce the production rate of sludge.Compared with the control bioreactor,addition of 4-nitrophenol caused a little variation of microorganism community structure and SVI value of the sludge,but barely affected the settleability of sludge.