Table 2.
Characteristics of raw biosludge, inoculum, and inoculum-to-substrate ratios based on COD used in the three biochemical methane potential (BMP) assays performed in this study.
| BMP 1 (Feb 02/2015) | BMP 2 (Mar 3/2015) | BMP 3a (Jul 07/2015) | |
|---|---|---|---|
| Raw biosludge characteristics | |||
| Biosludge (3 distinct samples for each BMP) | Sample 1 | Sample 2 | Sample 3 |
| TSS (g/L) | 18.8 (±0.7) | 18.6 (±0.3) | 20.1 (±0.8) |
| VSS (g/L) | 16.1 (±0.6) | 15.8(±0.1) | 17.6 (±0.8) |
| COD (g/L) | 24.2 (±0.4) | 25.2 (±1.8) | 27.8 (±2.8) |
| Granules (3 distinct samples for each BMP) | |||
| TSS (g/L) | 17.7 (±0.2) | 26.1(±1.3) | 19.9 (±1.7) |
| VSS (g/L) | 15.6 (±0.1) | 25.6 (±1.1) | 17.9 (±1.4) |
| COD (g/L) | 26.2 (±1.4) | 33.1 (±1.3) | 21.6 (±2.4) |
| COD contribution in BMP bottles (mg COD/bottle) | |||
| Granules (inoculum) | 86 | 122 | 151 |
| Biosludge (substrate)b | 200 | 150 | 200 |
| Inoculum to substrate ratioc | 0.4 | 0.8 | 0.8 |
a
Biosludge in BMP 3 was gamma irradiated.
b
COD was measured after enzymatic treatment.
c
Ratio was calculated based on COD.