Use of computer simulation for cycle length adjustment in sequencing batch reactor

The city of Nowy Targ located in Poland's highland operates the WWTP with classic SBR technology. In winter some decrease in process efficiency was observed. The research described in the paper was aimed at using computer simulation to adjust SBR cycle length and structure in order to minimize the effects of low wastewater temperature on biological CNP removal. The simulations performed at 6°C wastewater temperature showed that switching from 6 to 8 hours cycle and extension of the aeration phase length from 2.75 to 5 hours will increase the effectiveness of biological nitrification and biological phosphorus removal. The change in practice will not affect COD value in the effluent. Based on the simulation results a new SBR operational strategy was proposed for Nowy Targ WWTP.