分别运行升流式厌氧污泥床(UASB)反应器和连续流搅拌槽式反应器(CSTR)并使其达到稳定运行状态,在有机负荷率(OLR)均为6.0kg·m-3·d^-1的条件下,对比分析了二者在稳定期的运行特性和产甲烷菌群的组成。结果表明,UASB的化学需氧量(COD)去除率为95%,显著高于CSTR的COD 去除率(84%)。然而,CSTR系统中的活性污泥的比产甲烷速率(315L·kg^-1·d^-1)和比COD去除率(0.85 kg·kg^-1·d^-1)则显著高于UASB的260 L·kg^-1·d^-1和0.67 kg·kg^-1·d^-1。采用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)指纹分析技术对系统稳定期的活性污泥进行分析的结果表明,UASB系统的优势产甲烷菌为Methanosaeta concilii和Methanospirillum hungatei,而CSTR系统中的优势产甲烷菌为Methanosarcina mazeii和Methanobacterium formicicum。污泥微生物群落组成及其代谢特征的不同是造成厌氧处理系统效能差异的内在原因。UASB和CSTR在COD去除效能和污泥比活性方面各有所长,在实际应用中,须根据废水水质和预期处理程度合理选用。

The efficiency and the methanogens composition in an upflow anaerobic sludge blanket (UASB) reactor and a continuous stirred-tank reactor (CSTR) are investigated after achieving steady states at the same organic loading rate (OLR) of 6.0 kg·m-3·d^-1. The results show that the average removal rate of COD reaches 95% in the UASB, significantly higher than 84% of the CSTR. However, the specific methane production rate and the specific COD removal rate of the activated sludge are 315 L·kg^-1·d^-1 and 0.85 kg·kg^-1·d^-1, respectively, in the CSTR, notably higher than those of the UASB of 260 L·kg^-1·d^-1 and 0.67 kg·kg^-1·d^-1, respectively. The analysis of the methanogens composition of the activated sludge by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) indicates that Methanosaeta concilii and Methanospirillum hungatei are the dominant methanogens in the UASB, while Methanosarcina mazeii and Methanobacterium formicicum are dominant in the CSTR. The diversity of the microbial community composition and the metabolic characteristics are the underlying reasons for the difference in the performance of the anaerobic treatment system. The UASB and the CSTR have their respective advantages in the COD removal or specific activities of the activated sludge. It is reasonable to choose a perfect bioreactor (UASB or CSTR) for a practical engineering based on the quality of the wastewater and the required extent of the treatment.