Table 1 The effects of temperature and pH on VFA production at each experimental HRTs.

From: Potential and optimization of two-phase anaerobic digestion of oil refinery waste activated sludge and microbial community study

 

VFA concentration (mg/L)

HRT = 1 day

HRT = 2 days

HRT = 3 days

HRT = 4 days

HRT = 5 days

Temperature (pH = 6.0)

 55 °C

1131.2 ± 51.0

1801.5 ± 44.4

1764.8 ± 42.2

1499.3 ± 15.5

1311.7 ± 22.3

 35 °C

120.3 ± 13.3

120.5 ± 10.0

390.6 ± 12.7

486.4 ± 17.2

389.8 ± 9.8

pH (55 °C)

 5.0

672.4 ± 21.0

1132.5 ± 35.5

1178.5 ± 33.2

1052.0 ± 35.0

770.1 ± 41.4

 5.5

1069.2 ± 55.1

1609.8 ± 50.0

1592.6 ± 33.5

1546.6 ± 24.6

1132.5 ± 22.4

 6.0

1131.2 ± 27.5

1801.5 ± 47.6

1764.8 ± 41.3

1499.3 ± 36.6

1311.7 ± 36.0

 6.5

1460.3 ± 21.7

2754.0 ± 25.5

2142.1 ± 26.5

1875.3 ± 30.0

1475.5 ± 33.3

 7.0

1391.3 ± 36.6

2098.7 ± 35.5

1960.7 ± 43.6

1834.1 ± 44.8

1333.8 ± 25.9

  1. 95% confidence intervals are shown for each value.
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