2种启动方式下CSTR厌氧甲烷发酵系统的运行特性比较

厌氧产甲烷菌生长缓慢，对生境环境尤为敏感，其富集难且慢，所以厌氧反应器的快速启动一直是热点研究问题。为摸清连续流搅拌槽式反应器（CSTR）处理糖蜜废水的适宜启动条件和调控方法，比较了两种启动方式下CSTR厌氧甲烷发酵系统的运行特性。结果显示，以啤酒废水污水处理车间的剩余污泥为种泥，在HRT为18 h、温度35℃条件下，进水COD为4 000 mg·L-1时直接启动CSTR厌氧反应器，系统因挥发酸积累，产甲烷菌群活性受限，难以富集培养，经过近103 d的运行，系统未形成高效的厌氧甲烷发酵微生物菌群结构体系；而当采用保持HRT18 h不变，进水COD阶段性提升至4 000 mg·L-1的启动方式时，产甲烷菌群活性较高，能在较短时间内得到有效富集和培养，CSTR能成功培养具有完整甲烷发酵功能的微生物菌，COD去除率可在65 d内达到56%，反应器成功启动。

Comparing operational characteristics of anaerobic methanogenic fermentation in CSTR system under two different start-up conditions

As anaerobic methanogenic bacteria are particularly sensitive to environmental habits and grow slowly, successfully devising a quick start-up for anaerobic digestion reactors has been a topic for research. In this study, we compared the operational characteristics of anaerobic methanogenic fermentation in a continuous-flow stirred tank reactor (CSTR) system, in two different starting conditions. The aim was to explore the suitable conditions and regulatory methods for treating molasses wastewater by a CSTR. After inoculating the excess sewage sludge from a brewery wastewater treatment plant, the CSTR process was started with an influent of 4 000 mg·L-1 COD, and with the HRT being 18 h at 35℃. After operating for 103 days, the VFAs had accumulated in the reactor and the anaerobic methanogenic bacteria were inactive, suggesting that an efficient anaerobic microbial community was not present. However, when the HRT was maintained at 18 h, and the CSTR process was started by a stepwise increase of the influent COD to 4 000 mg·L-1, the methanogenic bacteria in the CSTR were active and it could be enriched and cultured effectively. The COD removal efficiency reached 56% during an operational period of 65 days, which indicated that a highly efficient anaerobic microbial community had been constructed successfully.