Performance Analysis and Microbial Community Evolution of In Situ Biological Biogas Upgrading with Increasing H₂/CO₂ Ratio

Table 1

Operational parameters during experimental periods; in brackets, next to the period number, the H₂/CO₂ ratio adopted.

Period–H2/CO2	Duration (d)	Progressive days (begin-end)	OLRSL (g COD·L^-1·d^-1)	OLRtot (g COD·L^-1·d^-1)
I	97^(a)	0-20
II−0.5	20	21-41
III–1	7	42-49
IV–2	8	50-58
V–3	8	59-67
VI–4	26	68-94
VII–6	12	95-107
VIII–7	33	108-141

^(a)In all figures, only the last 20 days of Period I are shown.