We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
新型好氧连续流反应器对活性污泥颗粒化的研究.
- Authors
贺向峰; 袁林江; 陈希; 朱淼; 牛泽栋; 周旭红; 王景华; 陈雪娇
- Abstract
A bench-scale reaction-precipitation integrated reactor (UOSB) coupled with a secondary sedimentation continu⁃ ous-flow apparatus (UOSB-ST), which featured small height-diameter ratio, was designed and built up. Subsequently, experiments were conducted probing into the effects of sludge screening and the shear stress of mechanical agitation on the sludge granulation. The experiments showed that when the apparent gas flow rate generated by aeration (shearing force) increased to 0.31 cm/s, and the flocculent sludge being inoculated in the reactor, the sludge volume index (SVI30) declined from 95 mL/g to 74.94 mL/g after 20-day operation; as a result, the mean particle size of the sludge grew up from 67.61 μm to 173.9 μm, the sedimentation speed increased to 10~27 m/h, the fractal dimension D2 was 1.995 8, Dpf being 1.069 5. Then it could be noted the sludge was of a compact structure with smooth and regular surface. So the effect of sludge granulated was remarkable. When continue to run the system to 25th day, filamentous bacteria began to grow on the surface of the granular sludge, causing the sludge SVI30 to rise rapidly to 252.87 mL/g. Then, applying mechanical stirring up to 300 rpm to increase horizontal shear stress, sludge aggregation and settling character could be improved in a short period of time: SVI30 reduced to 41.67 mL/g on 55 th day, and the average sludge particle size being 250.69 μm. The dominant flora of sludge belonged to denitrifying bacteria and the bacteria that were beneficial to EPS secretion. The experiments also showed there was key action to boost aerobic granulation of flocculent sludge owing to the'hydraulic selection'in the continuous flow system, i.e., the sedimentation area that had been initially formed on the upper part of the inverted funnel partition; and the shear stress by stir⁃ ring could only temporarily inhibit aerobic particles and excessive proliferation of filamentous bacteria on the sludge surface to reduce the SVI30.
- Subjects
SHEARING force; STRAINS &; stresses (Mechanics); FRACTAL dimensions; DENITRIFYING bacteria; GAS flow; FILAMENTOUS bacteria
- Publication
Environmental Science & Technology (10036504), 2022, Vol 45, Issue 7, p112
- ISSN
1003-6504
- Publication type
Article
- DOI
10.19672/j.cnki.1003-6504.0331.22.338