Comparison of saline wastewater treatment performance of SBR with repeated starvation under aerobic and non-aerobic conditions

摘要

This study investigated the effects of repeated starvation and feeding on the performance of ansequencing batch reactor (SBR) used for treating saline wastewater. The effects of aerobic andnnon-aerobic conditions on the sludge during starvation were evaluated to recover thenperformance of the SBR in terms of floc size and pollutant removal after resuming wastewaternfeeding. The floc size, fractal dimension, sludge volume index (SVI), specific oxygen uptake raten(SOUR), and pollutant removal efficiency were monitored. Experiment results revealed that thenfloc size and fractal dimensions decreased during starvation under both aerobic and non-aerobicnconditions and increased after re-feeding wastewater. However, the difference in floc physicalncharacteristics and performance depended on the starvation condition and was pronounced asnstarvation and re-feeding were repeated. The floc size and fractal dimensions decreased fromn152.7 to 72.2 and 1.98 to 1.79 at the end of the fourth starvation period, resulting in deteriorationnof the sludge settleability and effluent quality. On the other hand, the floc size and fractalndimensions decreased from 158.7 to 135.7 and 1.95 to 1.81 at the end of the fourth starvationnperiod but remained relatively constant after sludge adaptation. Some correlations were observednbetween the parameters monitored in this study. The results showed that maintaining the sludgenunder non-aerobic conditions was an effective strategy for reducing the effects of repeatednstarvation.