SBR工艺污泥沉降性能的影响因素研究

Study on Influencing Factors of Sludge Settleability in SBR

分别研究了运行方式、运行时间、硝酸盐浓度、曝气量、污泥负荷及曝气时间对SBR工艺中污泥沉降性能的影响。试验结果表明,以厌氧/好氧方式运行时,厌氧≥1 h且好氧≥3 h可获得沉降性良好的污泥;以缺氧/好氧方式运行时,缺氧段硝酸盐浓度过高会导致污泥膨胀,缺氧段时间宜控制在1 h左右;当有机负荷较高时,曝气量较高或较低均可能导致污泥膨胀,通过降低有机负荷可有效改善污泥沉降性能;在污泥负荷较低、曝气量适当且氮磷充足的条件下,曝气6 h时污泥的沉降性较差,将曝气时间延长至10 h,污泥浓度保持稳定,沉降性较好。

The influence of operation mode, operation time, nitrate concentration, aeration rate, sludge load and aeration time on sludge settleability was investigated in sequencing batch reactor （SBR）. The experimental results demonstrate that good sludge settleability can be obtained as running in anaerobic/aerobic mode with more than 1 h of anaerobic stage and more than 3 h of aerobic stage. As running in anoxic/aerobic mode, the sludge bulking can be resulted from excessive nitrate concentration in anoxic stage. The time of anoxic stage should be controlled at about 1 h. Under the condition of high organic load, the sludge bulking can be caused by higher or lower aeration rate, and the sludge setfleability can be improved effectively by reducing the sludge load. Under the condition of low sludge load, suitable aeration rate and sufficient nutrient concentration, the sludge setfleability is poorer by 6 h aeration time, nevertheless, the sludge concentration is stable and the settleability is better when the aeration time is prolonged to 10 h.