Table 5. Effect of sulfide removal by Alcaligenes sp. T307 in sulfide medium on biogas production over 5 days incubation.

Parameter (mg L^-1)^*

Control

Pre-treated by T307

 Effluent pH

8.76 ± 0.28

8.37 ± 0.10

 Effluent total sulfide

70.8 ± 1.70

12.1 ± 0.20

 Effluent dissolved sulfide

14.7 ± 0.57

10.0 ± 0.27

 Effluent H₂S

1.0 ± 0.15

1.1 ± 0.16

 Effluent sulfate

100.5 ± 6.36

143 ± 4.24

 Influent COD

5790 ± 61.47

4890 ± 49.1

 Effluent COD

3670 ± 56.57

2465 ± 39.5

 COD reduction (%)

36.62 ± 0.98

49.60 ± 1.01

 Biogas produced (ml L^-1d^-1)

85.5 ± 32.96

240 ± 24.86

 Biogas composition

 % CH₄

35.47 ± 12.99

48.06 ± 7.15

 % CO₂

63.67 ± 13.29

51.53 ± 7.18

 % H₂S

0.86 ± 0.69

0.41 ± 0.3

 Specific yield of CH₄ (ml g^-1 COD removed)

71.53 ± 18

237.81 ± 17