缺氧条件下进水时间与溶解氧对底物贮存的影响

采用6个缺氧-好氧SBR反应器,考察了进水时间及溶解氧(DO)浓度对活性污泥系统中底物贮存的影响.缺氧进水条件下,进水时间的长短对底物贮存影响并不明显.进水时间由10min长至60,90,120min,各SBR统内聚-β-羟基烷酸(PHA)贮存量依次小幅下降,最大差值为0.21mmolC/L,f_(PHB/HAc)值在0.84～0.90范围内波动.好氧曝气阶段控制低DO(0.5mg/L)运行比高DO(2.0mg/L)运行条件更有利于提高PHA的贮存量,90min进水时,高、低DO条件下PHA的平均合成量分别为3.1,5.0mmolC/L.而突然将进水时间90min缩短至10min,使得高、低DO系统中底物贮存量均增大,而高DO系统中底物贮存量的增长更为明显.

Effect of feeding length and dissolved oxygen on biochemical storage under anoxic conditions

Poly-β-hydroxyalkanoates (PHA), as one of internal polymers stored in microorganisms, plays an important role in the enhanced biological phosphorus removal process. Six identical anoxic-aerobic sequencing batch reactors (SBRs) were used to investigate the effect of feeding length and dissolved oxygen (DO) concentrations on biochemical storage of activated sludge. The results indicated that the feeding length had insignificant influence on biochemical storage under anoxic conditions. The storage levels of PHA were decreased slightly with gradual increasing of feeding length from 10min to 60min, 90min and 120min. The maximum difference was 0.21 mmolC/L and the fPHB/HAc was fluctuated between 0.84 and 0.90. Keeping DO to be low concentration in aerobic stage was more favorable for increasing the storage of PHA, compared to high DO concentration. The PHA storage amounts were 3.1 mmolC/L and 5.0 mmolC/L under high DO (2.0 mg/L) and low DO (0.5 mg/L) in two reactors with feed length of 90 min, respectively. The biomass acclimated to long feeding length could store more substrate when feeding length changing from long time into short time. Moreover, the PHA production amount was higher under high DO concentration than that under low DO concentration.