Selection of pretreatment method for enriching hydrogen-producing bacteria using anaerobic sewage sludge with three different substrates

ABSTRACT

The pretreatment of anaerobic sewage sludge by different methods (acid, base, Ethyline Diamine Tetra Acetic Acid (EDTA), chloroform, ammonia, heat-shock, aeration, microwave oven and chloroform) were conducted in batch tests to evaluate and compare their suitability in the enrichment of hydrogen-producing bacteria from three different carbon sources (glucose, sucrose and starch). Among the pretreatment methods, heat-shock and alkali show the higher hydrogen production at 6.5 initial pH and 35°C using 5 g/l substrate concentration. The combination of heat and alkali pre-treatment found to be the maximal hydrogen content of 71%, hydrogen production potential of 310 ml/l (1.73 mol/kg COD[chemical oxygen demand]), hydrogen production rate of 51.7 ml/h/l, hydrogen yield of 2.27mol/mol glucose and substrate degradation efficiency of 70%.

KEYWORDS:

• biohydrogen
• pretreatment
• dark fermentation
• mixed culture
• three different substrates

Acknowledgment

This work was supported by the financial assistance from Ministry of New and Renewable Energy (MNRE), INDIA, under National Mission mode project on ’Hydrogen production through Biological routes’ and Department of Science and Technology (DST), INDIA.

Disclosure statement

No potential conflict of interest was reported by the authors.