ZHU Zhao-ran,HUANG Xian-huai,TANG Yu-chao,et al.High Efficient Release of Carbon Source from Excess Sludge Disintegrated by Low-speed Stirring and Ball-milling[J].China Water & Wastewater,2021,37(13 13):1-6.
High Efficient Release of Carbon Source from Excess Sludge Disintegrated by Low-speed Stirring and Ball-milling
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第37卷
Number:
13 13
Page:
1-6
Column:
Date of publication:
2021-07-01
- Abstract:
- Traditional sludge anaerobic digestion technology has the disadvantages of a long residence time and high energy consumption. Therefore, excess sludge was physically disintegrated by a method of low speed stirring driving glass beads to squeeze and collide with each other, and effects of glass bead size, disintegration time, rotating speed and sludge/bead ratio on carbon source release were investigated. The dissolution rate of SCOD increased with the increase of disintegration time and rotating speed. However, the increase of SCOD was very slow when the disintegration time or speed reached a certain degree. The best excess sludge disintegration performance was obtained when glass bead particle size was 1-1.5 mm and sludge/bead ratio was 1 ∶2. After disintegrated for 3 hours with agitator edge linear speed of only 1.44 m/s, SCOD in the supernatant could reach 3 770 mg/L, and ammonia nitrogen and nitrate nitrogen could reach 25.2 mg/L and 43.7 mg/L, respectively. Under the same reaction conditions, the SCOD only increased by 10.3% and 2.5% after prolonging the disintegration time to 7 hours or increasing the linear velocity to 2.02 m/s, indicating that the carbon source release of the sludge was close to the maximum. Particle size analysis indicated that the sludge median particle size before and after disintegration was 28.114 μm and 2.233 μm, respectively. SEM showed that both the flocs and the cells were destroyed. Low-speed stirring and ball-milling disintegration method can fully release the carbon source of excess sludge at a lower energy consumption, which provides a new idea for solving the problem of excess sludge disposal and low carbon to nitrogen ratio sewage treatment.
Last Update:
2021-07-01