Abunde Sustainable Engineering Group (AbundeSEG), Ghana; Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, Trondheim, Norway; Institute for Marine Operations and Civil Engineering, Norwegian University of Science and Technology, Ålesund, Norway.
Department of Chemical Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Water Res. 2019 Oct 15;163:114891. doi: 10.1016/j.watres.2019.114891. Epub 2019 Jul 23.
Unlike high-rate anaerobic digesters that employ some mechanism to retain microbial sludge mass, low-rate systems use sufficiently long hydraulic retention times to ensure process stability, which becomes economically unattractive for treating large quantities of waste. This study presents the use of attainable region to develop a new strategy to enhance the stability of low-rate digesters. By considering three digestion cases, diary manure only (batch 1) or diary manure with granular (batch 2) or lagoon (batch) sludge as innoculum, the following findings were obtained. (1) For a given concentration of volatile acids in an anaerobic digester, higher concentrations of methanogenic archae can be attained using a digester structure (combination of different digesters) as opposed to single digester. (2) For a given digested substrate, a change in the source of inoculum results in a change in the limits of achievability by the system (attainable limits for batches 1, 2 and 3 were 46.486(g/L), 5.562(g/L) and 0.551(g/L), which resulted in performance improvements of 118.604%,175.627% and 200.436% respectively), and hence optimal digester structure. The evidence from this study suggests that the technique can be used to simultaneously improve process stability, define performance targets and propose digester structures required to achieve a given target.
与采用某种机制保留微生物污泥质量的高负荷厌氧消化器不同，低负荷系统使用足够长的水力停留时间来确保工艺稳定性，这对于处理大量废物来说在经济上是不可行的。本研究利用可达区域开发了一种新策略，以增强低负荷消化器的稳定性。通过考虑三种消化情况，即仅使用牛场粪便（批次 1）或使用颗粒状牛场粪便（批次 2）或沼液（批次）污泥作为接种物，得出以下发现。（1）对于厌氧消化器中给定的挥发性酸浓度，使用不同消化器（组合不同的消化器）结构而非单个消化器可以获得更高浓度的产甲烷古菌。（2）对于给定的消化底物，接种物来源的变化会导致系统可达性的变化（批次 1、2 和 3 的可达极限分别为 46.486(g/L)、5.562(g/L)和 0.551(g/L)，这分别导致性能提高了 118.604%、175.627%和 200.436%），从而优化了消化器结构。本研究的证据表明，该技术可用于同时提高工艺稳定性、定义性能目标并提出实现给定目标所需的消化器结构。
