As an energy-efficient and eco-friendly sludge treatment process, two-stage anaerobic digestion (AD) is widely employed to recovery biomass energy from waste sludge. However, the effect of primary and secondary sludge for two-stage AD was not clear. In this study, two-stage AD of mixed sludge in different volume ratio was investigated. The maximum cumulative H₂ yield (100.5 ml) and CH₄ yield (2643.6 ml) were obtained in volume ratio of 1:3 (primary sludge: secondary sludge). In two-phase AD, mixed sludge could induce positive effect on both organics releasing in extracellular polymeric substances (EPS) and the utilization of volatile fatty acids (VFAs). By investigating the compositional characteristics of dissolved organic matters (DOM) through excitation-emission matrix (EEM) coupling with fluorescence regional integration (FRI), it revealed more degradable substances utilization in mixture of sludge. Results from this work suggest that two-phase AD with mixed sludge is efficient for renewable energy recovery.

作为一种节能环保的污泥处理工艺，两段厌氧消化（AD）被广泛用于从废污泥中回收生物质能。然而，一级和二级污泥对两级 AD 的影响尚不清楚。在本研究中，研究了不同体积比混合污泥的两级 AD。最大累积 H ₂产量 (100.5 ml) 和 CH ₄以 1:3 的体积比（初级污泥：二级污泥）获得产量（2643.6 毫升）。在两相 AD 中，混合污泥可以对胞外聚合物 (EPS) 中的有机物释放和挥发性​​脂肪酸 (VFA) 的利用产生积极影响。通过激发发射矩阵（EEM）与荧光区域积分（FRI）耦合研究溶解有机物（DOM）的组成特征，揭示了污泥混合物中更多可降解物质的利用。这项工作的结果表明，混合污泥的两相 AD 可有效回收可再生能源。