升流式厌氧反应器以絮状污泥为种泥启动,启动过程主要关注COD去除率的提高以及污泥颗粒化的情况.污泥颗粒化过程包括“成核”以及“在核基础上成熟”2个步骤,“成核”作为颗粒化的起点尤为重要.本实验运用课题组建立的定量方法,研究了在低、中、高水力剪切力条件下的絮状污泥的成核过程.在成核过程中,污泥平均粒径(average sludge diameter,ASD)、含核率(nucleus ratio,NR)都与运行时间明显线性相关,ASD的增长速率分别为0.40、0.51和0.41μm·d^-1.中等水力条件下污泥的成核速度最快,相应的剪切速率为8.28s^-1,液相和气相上升流速分别为2.66和0.24m/h.高水力剪切力下,污泥的COD去除率增长快.同时污泥去除能力与污泥性质密切相关,在试验条件下,ASD的增长速率与COD去除率达到92%的快慢是一致的.
The keystones of the start-up of upflow anaerobic reactor with floeeulent sludge as seed include the improvement of COD removal and sludge granulation. The anaerobic sludge granulation consists of two steps, namely nucleation and maturation upon nuclei. The nucleation as the starting point is of particular importance. In this paper, the nucleation of floeculent sludge as seed under low, medium and high hydrodynamic shear conditions is studied with an original quantitative method. The average sludge diameters (ASD) or nucleus ratios show satisfactory linear correlations with the operation time during the nucleation and the average augmentation rate of ASD of 0.40, 0. 51 and 0.41μm · d^-1 respectively. The nucleation under the medium shear conditions of shear rate of about 8.28 s ^-1 which is corresponding to the superficial liquid and gas velocities of 2.66 and 0.24 m/h develops fastest. High hydrodynamic shear conditions enhance the improvement of COD removal of reactor. In this study the increase rate of ASD and the improvement rate of COD removal to 92% of sludge show consistent trend.