Enhanced biohydrogen production from oat straw co-digested with cow dung / sewage sludge by combined aerobic digestion and anaerobic fermentation

Abstract

Hydrogen was produced from oat straw by combined aerobic and anaerobic fermentation with fungi and cow dung. With aerobic pre-digestion, the maximum hydrogen production rate reached 133 ml/g volatile suspended solids per hour. The maximum hydrogen yield was 71.5 ml/g straw in 6 days by biological process. The lignocellulosic conversion of oak-straw waste was 39%, with the complex component converting 68% of the hemi-cellulose and 61% of the cellulose, but only 34% of lignin conversion. Aerobic pre-digestion by Trichoderma viride and Saccharomyces cerevisiae was significantly effective for lignin degradation. Combining aerobic digestion and anaerobic fermentation is a promising low-cost efficient and environmentally friendly method, not only for hydrogen production, but also for converting straw biomass.

Keywords

• Biohydrogen production
• aerobic digestion
• anaerobic fermentation
• pretreatment
• straw wastes