Strategies for enhancement of bio-hydrogen production using mixed cultures from starch effluent as substrate

ABSTRACT

The present study focused on the enhancement of hydrogen yield by using mixed culture (sewage sludge and/or slaughterhouse sludge) from starch effluent. The process parameters such as pH, temperature and substrate concentration were studied. The maximum hydrogen yield of 5.5 mol/kg chemical oxygen demand (COD) was obtained in the initial optimization study in the dark fermentation at pH, temperature and substrate concentration of 6.5, 55 °C and 15 g/L, respectively. To enhance the hydrogen production the two different strategies were applied at optimum conditions such as (i) a combination of two mixed cultures (anaerobic sewage sludge and slaughterhouse sludge), and (ii) addition of crude amylase to the hydrogen production reactor while using anaerobic mixed sludge as inoculum and starch effluent as substrate. These two strategies gave the maximum hydrogen yield of 8.1 and 7.1 mol/kg COD, respectively.

KEYWORD:

• Dark fermentation
• process parameters
• starch effluent
• co-mixed cultures
• crude amylase

Acknowledgments

This work was supported by financial assistance from the Department of Science and Technology (DST), under the Women Scientist Scheme with wide order number SR/WOS- A/ET- 109/2013 (G) dated 11 September 2014.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Department of Science and Technology, Ministry of Science and Technology [grant number SR/WOS- A/ET- 109/2013 (G)].