Table 7 Different combined pretreatment applied to the biogas production and yield

1

Park waste and cattle dung

Size reduction + alkali + fungal

Batch at 35 °C

102.6 L/kg VS

125.9 L/kg VS

[277]

2

Wheat straw

Ensiling + fungal

1 L Serum flask at 35 °C

66% increase in biogas yield

[278]

3

Rice straw

NaOH + hydrothermal

Batch at 37 °C

59.8 L/kg VS (CH₄)

132.7 L/kg VS (CH₄)

[109]

4

Cassava residue

Thermal + H₂SO₄

158 mL/g VS

248 mL/g VS

[279]

5

Sugar cane bagasse

Ethanol + NH₃

1.18 L Bioreactor at 35 °C

105.6 mL/g VS

299.3 mL/g VS

[280]

6

Wheat Straw

NH₃ (0.7%) + thermal (55 °C)

0.25 L reactor at 55 °C

407.8 mL/g VS

491.7 mL/g VS

[281]

7

Wheat Straw

NH₃ (0.7%) + thermal (105 °C)

0.25 L reactor at 55 °C

407.8 mL/g VS

538.1 mL/g VS

[281]

8

Sludge biomass

Fenton + ultrasonic

250 mL Serum bottle at 35 °C

0.16 gCOD/g COD

0.17 gCOD/g COD

[282]

9

WAS

CaCl₂ + bacteria

Batch reactor at 35 °C

0.145 L/g VS

0.322 L/g VS

[283]

10

WAS

Citric acid + ultrasonic

Batch reactor at 35 °C

0.212 L/g VS

0.433 L/g VS

[284]