Robust operation through effluent recycling for hydrogen production from the organic fraction of municipal solid waste

The stability of fermentative hydrogen production from the organic fraction of municipal solid waste (OFMSW) was evaluated in this work using a strategy of effluent recycling. Three pretreatment conditions were applied on the recycled effluent: a) no heat shock treatment, b) one initial heat shock treatment (90 degrees C, 30 min) and c) systematic heat shock treatment at the beginning of each fermentation. When a systematic heat shock was applied, a maximal hydrogen yield of 17.2 +/- 3.8 mLH(2)/gVS was attained. The hydrogen productivity was improved by 331% reaching a stable value of 1.51 +/- 0.29 mLH(2)/gVS/h, after 8 cycles of effluent recycling. This strategy caused a sharp decrease of diversity with stable co-dominance of hydrogenand lactate-producing bacteria, ie. Clostridiales and Lactobacillales, respectively. For the other conditions, a sharp decrease of the hydrogen yields was observed showing the importance of applying a heat shock treatment for optimal hydrogen production with effluent recycling.

Automated summary

Effluent recycling with systematic heat shock treatment significantly improves the stability and productivity of fermentative hydrogen production from organic waste, leading to a stable bacterial community structure dominated by hydrogen and lactate-producing bacteria.