一体式MBR污泥特性及对其过滤性能的影响

研究了一体式MBR长期不排泥运行的污泥特性变化,考察了水力停留时间、曝气量等因素对污泥增长特性、污泥颗粒粒径分布及膜过滤性能的影响,并探讨了这些因素之间的关系。结果表明:水力停留时间越短,MLSS与MLVSS增加越快,膜污染加速,膜过滤阻力增加越快,但MBR中污泥浓度的增长、变化对出水COD的影响不明显;污泥平均粒径随SRT的延长而减小,实验结束污泥粒径最小值为0.6μm大于实验用膜的孔径0.2μm,表明混合液中的微细颗粒污泥未对膜通量的下降起决定性作用,膜表面污泥的沉积对膜通量影响更大一些,增加曝气强度可以明显改善MBR的过滤性能。

RESEARCH ON INTEGRATED MBR SLUDGE CHARACTERISTICS AND ITS EFFECT ON FILTRATION PERFORMANCE

The growth characteristics of sludge in submerged MBR were investigated under the condition of long-term running without discharging sludge.Influences of hydraulic retention time(HRT),aeration and other factors on the growth characteristics of the sludge,sludge particle size distribution and membrane filtration performance were analyzed,and the relationship among these factors was also discussed.The results showed that when HRT was shorter,MLSS and MLVSS were increased faster,accelerating membrane fouling,increasing faster the filtration resistance of membrane in the system.The growth and change of sludge concentration in MBR had no significant effect on the effluent COD;Average particle size of sludge was decreased with the extension of SRT.The average diameter of sludge in initial domestication stages decreased to 0.6 μm,comparing to 0.2 μm of the test membrane pore size,sludge with fine particle of the mixture were not a main factor on the decreasing of membrane flux,the deposition of sludge on the membrane surface was more important,and increasing aeration intensity could significantly improve the performance of MBR filtration.