Effect of pH on the anaerobic acidogenesis of agroindustrial wastewaters for maximization of bio-hydrogen production: a lab-scale evaluation using batch tests.
The aim of this study was to investigate the impact of pH on the production of bio-hydrogen and end-products from a mixture of olive mill wastewater, cheese whey and liquid cow manure (with a ratio of 55:40:5, v/v/v). Batch experiments were performed under mesophilic conditions (37°C) at a range of pH from 4.5 to 7.5. The main end-products identified were acetic, propionic, butyric, lactic acid and ethanol. The highest hydrogen production yield was observed at pH 6.0 (0.642 mol H2/mol equivalent glucose consumed), whereas the maximum VFAs concentration (i.e. 13.43 g/L) was measured at pH 6.5. The composition of acidified effluent in acetic and butyric acid was similar at pH 6.0 and 6.5, albeit an increase of propionic acid was observed in higher pH. Lactic acid was identified as a major metabolite which presented an intense accumulation (up to 11 g/L) before its further bioconversion to butyric acid and hydrogen.
Chemical Engineering Department, University of Patras, 1 Karatheodori str., University Campus, 26500 Patras, Greece.
Margarita Andreas
MA
Dareioti
Chemical Engineering Department, University of Patras, 1 Karatheodori str., University Campus, 26500 Patras, Greece.
Aikaterini Ioannis
AI
Vavouraki
Chemical Engineering Department, University of Patras, 1 Karatheodori str., University Campus, 26500 Patras, Greece. Electronic address: kornaros@chemeng.upatras.gr.
Michael
M
Kornaros
D000383:Agriculture; D000693:Anaerobiosis; D061249:Batch Cell Culture Techniques / Q000379:methods*; D001673:Biodegradation, Environmental; D056804:Biofuels; D020148:Butyric Acid / Q000378:metabolism; D050260:Carbohydrate Metabolism; D002264:Carboxylic Acids / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000096:biosynthesis; D006859:Hydrogen / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007700:Kinetics; D019344:Lactic Acid / Q000096:biosynthesis; D062065:Wastewater / Q000382:microbiology
D056804:Biofuels; D020148:Butyric Acid; D002264:Carboxylic Acids; D000431:Ethanol; D005232:Fatty Acids, Volatile; D006859:Hydrogen; D007220:Industrial Waste; D019344:Lactic Acid; D062065:Wastewater
Acidogenesis; Agro-industrial wastes; Anaerobic digestion; Hydrogen; pH effect