Department of Infrastructure, Universität Innsbruck, Technikerstraße 13, A-6020 Innsbruck, Austria.
MCI, The Entrepreneurial School, Maximilianstraße 2, 6020 Innsbruck, Austria.
Bioresour Technol. 2024 Aug;406:131095. doi: 10.1016/j.biortech.2024.131095. Epub 2024 Jul 8.
The efficiency of anaerobic digestion (AD) processes is intricately tied to mixing quality. This research investigates the influence of two impeller types, namely a helical ribbon impeller (HRI) and a pitched-blade impeller (PBI), on key aspects of AD. The investigation encompassed mixing dynamics, methane production, microbial communities, and the previously unexplored impact on digestate dewaterability. Results show that agitation with the PBI exhibited stratification, with bottom layer total solids (TS) values of 3.1% for the PBI and 2.6% for the HRI. Nevertheless, methane yield remained unchanged, averaging 286 L/kg volatile solids (VS). Slower mixing with the HRI achieved more uniform mixing and reduced energy requirements. Additionally, impeller type significantly affected digestate dewaterability, leading to a 3.8% increase in TS of the dewatered sludge when using the PBI. These findings highlight the importance of considering mixing not only for methane production and reduced maintenance but also for achieving optimal digestate dewaterability.
厌氧消化（AD）过程的效率与混合质量密切相关。本研究调查了两种叶轮类型，即螺旋带式叶轮（HRI）和斜叶桨式叶轮（PBI），对 AD 的关键方面的影响。研究包括混合动力学、甲烷产量、微生物群落，以及以前未探索的对消化物脱水性能的影响。结果表明，PBI 搅拌存在分层现象，底层总固体（TS）值为 PBI 的 3.1%，HRI 的 2.6%。然而，甲烷产量保持不变，平均为 286 L/kg 挥发性固体（VS）。HRI 搅拌较慢，实现了更均匀的混合，降低了能源需求。此外，叶轮类型对消化物脱水性能有显著影响，使用 PBI 时脱水污泥的 TS 增加了 3.8%。这些发现强调了不仅要考虑甲烷生产和减少维护，还要考虑实现最佳消化物脱水性能的重要性。
