Abstract:The effects of different concentrations of Cu2+ ion on the removal of CODCr, TN and TP in sequencing batch reactor (SBR) system were investigated, and the ToxTell biosensor with activated sludge was also constructed to determine the toxicity of Cu2+. The results show that there are not distinct impacts on the SBR process when Cu2+ concentration is within 10 mg·L-1, and when it is over 20 mg·L-1, the effluent water quality decreases obviously, the activated sludge quantity and settling velocity(SV) reduce, and the sludge floc begins to disintegrate. The toxicity determined with ToxTell biosensor is corresponding to the CODCr, TN and TP removal performance, which shows that the ToxTell biosensor can be used well in the early warming determination of Cu2+ in the SBR process.