Effect of carbonate on anaerobic acidogenesis and fermentative hydrogen production from glucose using leachate as supplementary culture under alkaline conditions

Carbonate was added into a co-culture of glucose and fresh leachate under alkaline condition to enhance batched acidogenesis and fermentative hydrogen production simultaneously. Results indicated carbonate has positive effect on both H2 production and acetic acid generation. The highest hydrogen yield (about 1.40 mol/mol glucose) was obtained at [CO32-] = 280 mg/L with pH 8.0 and [CO32-] = 560 mg/L with pH 9. The dominant liquid metabolites were ethanol, acetic and butyric acid. The highest total volatile fatty acid yield (0.38 g/g glucose) was achieved at [CO32-] = 560 mg/L with pH 9. In this case, the acetic acid yield reached 0.13 g/g glucose. Verification tests using simulated wastewater as substrate were also carried out at pH 9. Results demonstrated calcium ions inhibit hydrogenogens activity while carbonate addition can alleviate the suppression effect caused by Ca2+.

► Simultaneous hydrogen production and acidogenesis using fresh compost leachate as nutrient source.
► Carbonate addition improve both the hydrogen production and acidogenesis performance.
► pH 9 is the optimal condition for both processes.
► Using leachate as nutrient source make positive effects on anaerobic fermentation.