以脱水污泥为接种污泥促进好氧污泥颗粒化

Enhancing aerobic granulation by seeding dewatered sludge

以脱水造粒形成的物理颗粒污泥为接种污泥,明显提高了好氧污泥颗粒化速度.研究结果表明:在第20d,接种物理颗粒污泥的R2中90%以上的污泥粒径即大于0.2mm,而接种絮状污泥的R1中只有26.7%.颗粒化过程中,接种物理颗粒污泥的R2中SVI始终小于80m L/g沉降性能良好,第25d时污泥浓度为6300mg/L,而R1为3200mg/L.脱水过程未对污泥活性造成明显影响,培养期间两者COD去除率均大于90%,但培养后期R2中TN的去除率约为70%,明显优于R1的55%,其主要原因为R2中的污泥粒径大于R1.经过5d的曝气剪切后仍有39.8%的物理颗粒污泥大于0.2mm,为颗粒化提供了大量诱导核,同时物理颗粒污泥内部营养传输孔道的形成与EPS的內源消化和反硝化产气有关.

Physical granular sludge formed by dewatering as seed sludge, significantly enhanced aerobic granulation. Onday 20, there was 90% of sludge larger than 0.2mm in R2 seeded with physical granular sludge,and only 26.7% was in R1seeded with flocculent sludge. The SVI of R2 maintained below 80mL/g meaning better settleability.Compared with3200mg/L of MLSS in R1, R2 had a much higher MLSS at 6300 mg/L on day 25.In the whole process, COD removal rateof both reactor exceeded 90%, suggesting sludge activity was not obviously decreased by dewatering, but TN removal ratewas about 70% in R2 superior than the 55% in R1on account of the lager particles size in R2. Experienced 5 days shearing,39.8% of physical granular sludge were still larger than 0.2 mm providing plentiful cores for aerobic granulation, andnutrition transmission channel was formed inside physical granular sludge by endogenous digestion of EPS and gasescaping of denitrification.