College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China; Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark.
Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark; Soil and Water Resources Institute, Hellenic Agricultural Organisation- DEMETER, 57001 Thermi-Thessaloniki, Greece.
Sci Total Environ. 2021 Jun 15;773:144981. doi: 10.1016/j.scitotenv.2021.144981. Epub 2021 Jan 29.
The aim of this work was to provide solid proofs regarding the achievement of "steady-state conditions", which means that the performance of the anaerobic digester is representative of the applied environmental conditions. For this reason, we investigated how, starting from different inoculum sources (i.e., municipal wastewater treatment, bio-waste treatment, and agricultural waste biogas plant), the microbial community adapted to the operational parameters and led to stable biogas production in thermophilic digesters treating the same influent feedstock. The results revealed that the different system achieved similar process performance and microbial community structure after a period that was equal to four hydraulic retention times, approved by a constant pH of 7.89 ± 0.08, 7.92 ± 0.05 and 7.85 ± 0.08, respectively, and stable TAN concentration of 1500 mg/L. Moreover, it was found that the microbial composition of the inocula was a key factor for the speed of achieving stable process performance; thus, a pre-adapted to the influent feedstock inoculum can shorten the stabilization process. On the contrary, after long term reactor operation, the microbial structure was shaped according to the chemical composition of the influent feedstock. The results of the study can also be used as a guide in future researches on anaerobic degradation, particularly in determining the time interval of an experiment to reflect changes in the microbial community of anaerobic digester.
本研究旨在提供关于“稳态条件”实现的可靠证据，这意味着厌氧消化器的性能代表了所应用的环境条件。为此，我们研究了在不同的接种物来源（即城市污水处理、生物废物处理和农业废物沼气厂）的情况下，微生物群落如何适应操作参数，并在处理相同进料的高温消化器中稳定产生沼气。结果表明，不同的系统在经过四个水力停留时间相等的时间后，达到了相似的工艺性能和微生物群落结构，这得到了 pH 值为 7.89±0.08、7.92±0.05 和 7.85±0.08 的恒定值、稳定的 TAN 浓度 1500mg/L 的证实。此外，还发现接种物的微生物组成是实现稳定工艺性能的速度的关键因素；因此，预先适应进料的接种物可以缩短稳定化过程。相反，在长期的反应器运行后，微生物结构根据进料的化学成分形成。研究结果还可作为未来厌氧降解研究的指导，特别是在确定反映厌氧消化器微生物群落变化的实验时间间隔方面。
