Research on Nitrogen and Phosphorous Removal and Membrane Fouling Characteristics of Two-Stage Sequencing Batch MBR

Aiming at resolving problems in biological nitrogen and phosphorous removal process like conflict between nitrogen removal and phosphorous removal and total phosphorous in the effluent due to unsatisfied solid-fluid separation, two-stage sequencing batch membrane bioreactor (TSBMBR) was presented in treating municipal wastewater. Influence of two-stage sequencing batch operation mode on pollutants removal efficiency was investigated. The results indicated that through the control of operation conditions, phosphorous accumulating organisms (PAOs) and nitrification bacteria can propagate separately in each stage of reactor. Nitrogen and phosphorous removal conflict could be resolved, and TP, TN, NH₃-N in the effluent could reach scenic environmental water criteria. Comparing with one-stage membrane bioreactor, the combination of sequencing aeration, intermittent membrane suction and idle aeration operation mode could enable the system keep high trans-membrane flux, low membrane fouling rate and high system stability.