Biomethanation from enzymatically hydrolyzed brewer's spent grain: Impact of rapid increase in loadings.
Enzymatically hydrolyzed brewer's spent grain (BSG) was digested in two expanded granular sludge beds (EGSBs, named BSG1 and BSG2, respectively). Both reactors were operated with the same organic loading rate (OLR) from 1 to 10kgCODm(-3)d(-1) during the first 45days. Hereafter a rapid OLR increase was applied to BSG2 from 10 to 16kgCODm(-3)d(-1) within three weeks, while the OLR of BSG1 was increased by less than 2kgCODm(-3)d(-1) in the same period. Results showed that a 30% decrease in COD removal and 70% decrease in methane yield appeared in BSG2 after the rapid OLR increase, and volatile fatty acid (VFA) accumulated more than thirty times compared to BSG1. The biomass structure deteriorated and 15% of the biomass was lost from the BSG2 reactor. 454-PyroTag and qPCR analysis revealed a rapid growth of acidifiers (i.e., Bacteroides) and a unique microbial community in BSG2 following the rapid increase in OLR.
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150090 Harbin, China; Section of Sanitary Engineering, Department of Water Management, Delft University of Technology, No. 1 Stevinweg, 2600 CD Delft, The Netherlands.
Haoyu
H
Wang
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150090 Harbin, China; Section of Sanitary Engineering, Department of Water Management, Delft University of Technology, No. 1 Stevinweg, 2600 CD Delft, The Netherlands.
Yu
Y
Tao
DSM Biotechnology Center, P.O. Box 1, 2600 MA Delft, The Netherlands.
Margarida
M
Temudo
DSM Biotechnology Center, P.O. Box 1, 2600 MA Delft, The Netherlands.
Henk
H
Bijl
DSM Biotechnology Center, P.O. Box 1, 2600 MA Delft, The Netherlands.
Joris
J
Kloek
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 150090 Harbin, China. Electronic address: rnq@hit.edu.cn.
Nanqi
N
Ren
Section of Sanitary Engineering, Department of Water Management, Delft University of Technology, No. 1 Stevinweg, 2600 CD Delft, The Netherlands.
Jules B
JB
van Lier
Section of Sanitary Engineering, Department of Water Management, Delft University of Technology, No. 1 Stevinweg, 2600 CD Delft, The Netherlands.
Merle
M
de Kreuk
D001439:Bacteroides / Q000145:classification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D049109:Cell Proliferation / Q000502:physiology; D006867:Hydrolases / Q000737:chemistry*; D006868:Hydrolysis; D007220:Industrial Waste / Q000517:prevention & control; D008697:Methane / Q000302:isolation & purification / Q000378:metabolism*; D059013:Microbial Consortia / Q000502:physiology; D012037:Refuse Disposal / Q000379:methods; D012722:Sewage / Q000382:microbiology*; D000067348:Whole Grains / Q000737:chemistry* / Q000378:metabolism*
D007220:Industrial Waste; D012722:Sewage; D006867:Hydrolases; D008697:Methane
Biogas; Brewer’s spent grain (BSG); Expanded granular sludge bioreactors (EGSB); Microbial community; Organic loading rate (OLR)