The concept of bio-hydrogen generation was also tested using
industrial process wastewaters such as palm oil mill effluent,
which resulted in 0.42 L biogas/g COD destroyed with a
hydrogen content of 57±2% at 7 days HRT [20]. While the
beer brewery wastewater yielded 0.47m3 biogas/kg COD destroyed
with a hydrogen content of 60% [21]. The anaerobic
acidogenesis of high strength rice winery wastewater resulted
in a hydrogen yield of 1.37–2.14 mol/mol-hexose with a hydrogen
content of 53–61% [22]. The bio-hydrogen generation
from starch wastewater was investigated at 55 ◦C for varying
pH (4–9) and starch concentrations (92–36.6 g/L). The result
showed a maximum hydrogen yield of 92 mL/g of starch at pH
6, while the maximum specific hydrogen production rate was
365 mL/gVSS d at pH 7 with hydrogen content of 60% [23].
The hydrogen production by Clostridium thermolacticum from
waste stream of dairy industry resulted in a specific hydrogen
production greater than 5 mmolH2 (g cell)
−1 h−1 [24]. In the
case of co-digestion of food waste with sewage in the ratio
87:13 resulted in a hydrogen production potential of 122.9 mL/g
carbohydrate-COD [25]. The kinetic experiment on hydrogen
producing bacteria was investigated using substrates like sucrose,
non-fat dry milk and food waste. The results showed that
the hydrogen yield was 234, 119 and 101 mL/g-COD, respectively
[26]. Whereas, the effect of acetylene and bromoethanesulfonate
(BES) inhibition on methanogenesis coupled with