GAOLi-juan,WANGZhi,WANGYi,et al.Effect of Biochar on Continuous Operation of Sludge Thermophilic Anaerobic Digestion System[J].China Water & Wastewater,2023,39(17):26-31.
Effect of Biochar on Continuous Operation of Sludge Thermophilic Anaerobic Digestion System
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第39卷
Number:
第17期
Page:
26-31
Column:
Date of publication:
2023-09-01
- Keywords:
- excess sludge; thermophilic anaerobic digestion; biochar; continuous operation; biogas production stability
- Abstract:
- This paper investigated the methanogenic characteristics and the changes of volatile fatty acids (VFAs) with time in a thermophilic anaerobic digestion (TAD) system, and analyzed the microbial community composition and digestate properties, so as to explore the effects of biochar addition on continuous operation of TAD of excess sludge from municipal wastewater treatment plant. The addition of biochar promoted the degradation of VS and VFAs in sludge, improved the methane content, biogas production and stability of biogas production. When the organic load rate was 2.87 g/(L·d) (calculated as VS), the average methane production rate of TAD system with biochar addition was 96.89 mL/(gVS·d), which was 11.96% higher than that of the control group, and the mean deviation of daily biogas production was reduced by 5.54%, indicating that the biogas production was relatively stable. In addition, the addition of biochar also significantly affected the microbial community composition, promoted the interspecific direct electron transfer and syntrophic metabolism of methanogens and bacteria, and significantly increased the relative abundance of hydrotrophic methanogens in TAD. The addition of biochar reduced the TP and PO43--P in biogas slurry by 24.42% and 34.46%, and increased the contents of nitrogen, phosphorus and potassium as well as the contents of plant secondary macronutrients and micronutrients in digestate. Therefore, the addition of biochar was beneficial to the stability of sludge TAD system in continuous operation, increased the methane yield and improved the properties of digestate.
Last Update:
2023-09-01