RT Journal Article
SR Electronic
T1 The feedstock microbiome selectively steers process stability during the anaerobic digestion of waste activated sludge
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 757922
DO 10.1101/757922
A1 Cindy Ka Y Law
A1 Rens De Henau
A1 Jo De Vrieze
YR 2019
UL http://biorxiv.org/content/early/2019/09/05/757922.abstract
AB Strategies to enhance process performance of anaerobic digestion remain of key importance to achieve further spreading 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 performance 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 performance between the digesters fed fresh and sterile WAS, and process recovery was obtained even at the highest salt pulse of 25 g Na+ L−1. Feedstock sterilisation strongly impacted the microbial community in the digesters. In conclusion, feedstock inoculation can be considered a cheap, yet, disturbance-specific strategy to enhance process stability in full-scale anaerobic digestion processes.