High-solids thermophilic anaerobic digestion of sewage sludge: effect of ammonia concentration
High-solids thermophilic anaerobic digestion of sewage sludge: effect of ammonia concentration
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DOI：
10.1007/s10163-020-01117-z
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发表时间：
2021-01
影响因子：
3.1
通讯作者：
M. Takashima;J. Yaguchi
中科院分区：
文献类型：
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作者：
M. Takashima;J. Yaguchi
以7%~8%和9%~10%的污泥为原料，在水力停留时间为20天的条件下，进行了高固体分高温厌氧消化试验。投加7~8%污泥的厌氧消化池运行成功，挥发性固形物(VS)损失率为57.8%，标准温度和压力下甲烷产率为0.327×L/gVS。当投加9-10%的污泥时，对照消化池在运行约80天后出现翻车现象。总氨氮(TAN)在2500mGN/L或以上时，对厌氧微生物有抑制作用。另一个消化池采用侧流结构(80℃，2h，氢氧化钠初始pH为9，回流比为70%)对消化污泥进行每周间歇氨气吹脱，保持了1720mgN/L的平均TAN，能够在没有氨抑制的情况下继续运行。TAN比游离氨氮(FAN)是更好的氨抑制指标。微生物分析表明，消化污泥的微生物多样性较差，细菌类为梭状芽胞杆菌，古生菌属以甲烷热细菌和甲烷肉芽孢杆菌为主。综上所述，只要适当控制消化池中的TAN，高固体分高温厌氧消化可以容纳高达10%的进水污泥。
High-solids thermophilic anaerobic digestion fed with sewage sludge of 7–8% and 9–10% total solids was investigated at the hydraulic retention time of 20 days in this lab-scale study. The anaerobic digester fed with 7–8% sewage sludge was successfully operated, resulting in volatile solids (VS) destruction of 57.8% and methane production of 0.327 L/gVS (at standard temperature and pressure). When fed with 9–10% sewage sludge, the control digester was upset after about 80 days of operation. Total ammonia nitrogen (TAN) of 2500 mgN/L or more caused inhibition to anaerobic microorganisms. Another digester combined with weekly batch ammonia stripping of digested sludge in a side-stream configuration (80 °C, 2 h, initial pH of 9 with NaOH and return ratio of 70%), was maintained at the average TAN of 1720 mgN/L, and was able to continue without ammonia inhibition. TAN was a better indicator on inhibition of ammonia than free ammonia nitrogen (FAN). Microbial analysis revealed poor microbial diversity of digested sludge, that is, Class Clostridia for Bacteria and GeneusMethanothermobacterandMethanosarcinafor Archaea were predominated. In conclusion, high-solids thermophilic anaerobic digestion can accommodate the influent sewage sludge up to 10%, as far as TAN is properly controlled in digester.