LI Jin-he,ZHANG Bo-tao,LIU Bao-yu,et al.Optimal Reaction Temperature in Mesophilic Anaerobic Digestion of Waste Activated Sludge and Its Promotion Mechanism[J].China Water & Wastewater,2021,37(3 3):9-15.
Optimal Reaction Temperature in Mesophilic Anaerobic Digestion of Waste Activated Sludge and Its Promotion Mechanism
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第37卷
Number:
3 3
Page:
9-15
Column:
Date of publication:
2021-02-01
- Abstract:
- Mesophilic anaerobic digestion of waste activated sludge in China is hindered by low organic dry solids degradation efficiency, slow fermenting rate and restricted methanogenic production. In order to improve this situation, the impact of reaction temperature on methane (CH4) generation of anaerobic digestion based on a sludge treatment plan in Tianjin was assessed through lab-scale, pilot-scale and full-scale test. Also, the promotion mechanism of anaerobic CH4 production was investigated. The biochemical methane potential (BMP) at 40 ℃ and 45 ℃ increased by 28.4% and 37.5% respectively, compared with that at 35 ℃. The average CH4 generation in the experimental digester at 40 ℃ was 25.5% higher than that in the control digester at 35 ℃ during stabe period on 200-litre scale, and the methane content in biogas was equivalent at the two temperatures. After the reaction temperature of manufacturing digesters was adjusted from 35 ℃ to 40 ℃, an approximate 40% increase of CH4 yield (expressed as cumulative CH4 volume per volatile solid mass fed) was observed according to the running records of previous years. The mechanisms investigation for improved CH4 generation showed that the rates of solubilization, hydrolysis and acidification of waste activated sludge at 40 ℃ were accelerated by 73.3%, 50.0% and 34.7% respectively than those at 35 ℃, which was beneficial to providing more substrates for subsequent CH4 generation. It was found that the methanation process at 40 ℃ was almost the same as that at 35 ℃ for undomesticated activated sludge. For domesticated activated sludge at 40 ℃ lasted for half a year, it caused 20.5% higher of the methanogenesis rate and 12.2% higher of CH4 generation compared with the data at 35 ℃. As a more economical, environmental and efficient process, this approach possesses value of promotion and application.
Last Update:
2021-02-01