GAOLi-juan,WANGMiao,WANGYi,et al.Long-term Operation Performance of Excess Sludge Anaerobic Digestion under Mesophilic and Thermophilic Conditions[J].China Water & Wastewater,2023,39(19):27-32.
Long-term Operation Performance of Excess Sludge Anaerobic Digestion under Mesophilic and Thermophilic Conditions
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第39卷
Number:
第19期
Page:
27-32
Column:
Date of publication:
2023-10-01
- Keywords:
- thermophilic anaerobic digestion; long-term operation; microbial community; energy balance calculation
- Abstract:
- This study designed two continuous mesophilic and thermophilic excess sludge anaerobic digestion systems under different organic loading rates (OLR), analyzed the effects of temperature and OLR on sludge anaerobic digestion (AD), and preliminarily calculated the energy production and consumption of the systems, so as to solve the high energy consumption problem of sludge thermophilic anaerobic digestion (TAD). According to the bench-scale experiment operated continuously for 130 days, the methane yield per unit volume of TAD reached 419.5 mL/(L·d) when the OLR was 2.87 g/(L·d) (measured as VS), which was 2.9 times that of the mesophilic anaerobic digestion (MAD) system, and 1.6 times that of the TAD system when the OLR was 1.79 g/(L·d). Besides, the soluble chemical oxygen demand (SCOD), total ammonia nitrogen (TAN) and free ammonia (FAN) in the TAD system under different OLRs were higher than those in the MAD system, whereas the concentrations of volatile fatty acids (VFAs) were not much different from those in the MAD system. In addition, Methanosarcina was the dominant archaea in the TAD system (56.4%), while Methanothrix was the dominant archaea in the MAD system (56.9%). The energy balance calculation showed that the TAD system could achieve energy self-sufficiency, while the MAD system required additional energy input. In general, the TAD system had better performance of hydrolysis and gas production than those of the MAD system, and could realize the energy self-sufficiency. Therefore, TAD has more obvious advantages in the energy production of excess sludge in municipal wastewater treatment plants.
Last Update:
2023-10-01