颤蚓对活性污泥沉降性能的影响

Effect of Tubificidae on activated sludge settling performance

系统考察了低、中、高3种不同污泥浓度下（TSS≈4.gL^-1、6.gL^-1和8.gL^-1）,一定的颤蚓投加比例对活性污泥沉降性能的影响,并同时考察了颤蚓对污泥特性的影响.研究结果表明,投加颤蚓后60min内,活性污泥沉降速率明显加快,60min时的污泥容积相对于未投加颤蚓前可减少8%~42%;而且,这种效应对污泥浓度高的活性污泥更为显著和有效.然而,通过对污泥特性的分析表明,颤蚓在短时间内（1~3h）对污泥平均粒径、Zeta电位并无多少影响;此时污泥容积指数（SVI）和胞外聚合物含量（EPS）却反而略有增加.

Recently Tubificidae （Oligochaete：Tubificidae） has been observed to have potential to improve sludge settling and it is widely applied in the study of sludge reduction. The purposes of this study were therefore to systematically investigate the effect on sludge settling performance induced by Tubificidae. The worms were inoculated at various addition ratios into sludge of different TSS concentrations （TSS≈4.gL^-1、6.gL^-1 ＆ 8.gL^-1 ） and the resulting sludge characteristics were measured to understand the effects of Tubificidae addition. Results showed that a rapid and dramatic enhancement of sludge settling rate was observed within 60 minutes after Tubificidae addition, especially for sludge with high TSS concentration. Compared with the sludge without Tubificidae,the sludge volume at various TSS concentrations can be reduced by 8% ~ 42% within 60 min after worm inoculation. Sludge characterization studies showed that the mean floc size and Zeta potential of activated sludge changed little after addition of Tubificidae, though SVI and extra-cellular polymeric substances （EPS） concentrations were slightly increased within a short-term after worm inoculation.