Faculty of Bioscience Engineering, Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, B-9000, Ghent, Belgium.
Appl Microbiol Biotechnol. 2020 Apr;104(8):3675-3686. doi: 10.1007/s00253-020-10472-8. Epub 2020 Feb 22.
Strategies to enhance process performance of anaerobic digestion remain of key importance to promote wider usage of this technology for integrated resource recovery from organic waste streams. Continuous inoculation of the microbial community in the digester via the feedstock could be such a cost-effective strategy. Here, anaerobic digestion of fresh waste activated sludge (WAS) was compared with sterilized WAS in response to two common process disturbances, i.e. organic overloading and increasing levels of salts, to determine the importance of feedstock inoculation. A pulse in the organic loading rate severely impacted process stability of the digesters fed sterile WAS, with a 92 ± 45% decrease in methane production, compared to a 42 ± 31% increase in the digesters fed fresh WAS, relative to methane production before the pulse. Increasing salt pulses did not show a clear difference in process stability between the digesters fed fresh and sterile WAS, and process recovery was obtained even at the highest salt pulse of 25 g Na L. Feedstock sterilization through thermal pretreatment strongly impacted the microbial community in the digesters. In conclusion, feedstock thermal pretreatment strongly impacted anaerobic digestion process stability, due to feedstock inoculation and compositional modification.
为促进有机废物资源综合回收利用，提升厌氧消化工艺性能的策略依然至关重要。通过进料向消化器中连续接种微生物群落可能是一种具有成本效益的策略。本研究中，新鲜剩余活性污泥（WAS）的厌氧消化与灭菌 WAS 的厌氧消化进行了对比，以响应两种常见的工艺干扰，即有机负荷过高和盐度增加，从而确定进料接种的重要性。有机负荷率的脉冲对灭菌 WAS 进料消化器的稳定性产生了严重影响，与脉冲前相比，甲烷产量降低了 92±45%，而新鲜 WAS 进料消化器的甲烷产量则增加了 42±31%。增加盐脉冲并没有显示出新鲜和灭菌 WAS 进料消化器在工艺稳定性方面的明显差异，即使在 25 g Na L 的最高盐脉冲下，也获得了工艺恢复。通过热预处理对原料进行灭菌强烈影响了消化器中的微生物群落。总之，由于原料接种和组成改性，原料的热预处理强烈影响了厌氧消化工艺稳定性。
