Utilization of distillery wastewater for hydrogen production in one-stage and two-stage processes involving photofermentation

• Published in: Enzyme and microbial technology 2018-03, Vol.110, p.1-7
• Main Authors: Laurinavichene, Tatyana, Tekucheva, Darya, Laurinavichius, Kestutis, Tsygankov, Anatoly
• Format: Article
• Language: English
• Subjects: Dark fermentation; Distillery wastewater; Hydrogen production; Photofermentation; Purple bacteria
• ISSN: 0141-0229; 1879-0909
• DOI: 10.1016/j.enzmictec.2017.11.009

•17.6L H2 can be produced from 1L of distillery waste by dark+photo fermentation.•An estimated 4–8% of energy consumed in ethanol production might be recovered as H2.•Integrated process resulted in wastewater purification from sugars and VFAs.•Further efforts should be directed to optimize the scale-up process. In this study, distillery wastewater was treated by dark fermentation or photofermentation alone, and by sequential dark and photofermentation processes using anaerobic saccharolytic consortium and purple nonsulfur bacteria. Combination of dark and photofermentation resulted in the maximal H2 yield of 17.6L/L of distillery waste with chemical oxygen demand 40g/L. It is equivalent to 205kJ/L distillery wastewater and corresponds to recovery of approximately 4–8% of energy consumed during ethanol production. Optimal performance of photofermentation was observed at 20% concentration of pre-fermented distillery waste. In photofermentation, the range of the suitable distillery waste concentrations was extended and the H2 yield was improved by choosing the tolerant strain of purple bacteria Rhodobacter sphaeroides B-3059. After two stages, organic acids and sugars were completely consumed that means wastewater treatment concomitant to H2 production.