Biohydrogen production by co-digestion of food waste and corn industry wastewater

Abstract

Food waste (FW) and corn industry wastewater (cornWW) are residues with a high potential for hydrogen production in the dark fermentation process. The study aimed to identify the co-digestion of FW and cornWW ratios for improving hydrogen production and evaluating the synergistic effect on biohydrogen production potential (BHP) in batch test. The inoculum consisted of a mixed culture plus the native microbiota of each substrate. The adjustment of the initial pH to 7.5 was compared to the co-digestion without control of the initial pH of the experiments. The highest hydrogen and metabolites production were obtained with a co-digestion FW:cornWW ratio. When no pH adjustment is applied, pH values above 10 completely inhibit the metabolic activity of bacteria in the process. The cornWW not only provided alkalinity to the system but also can be applied to adjust the organic matter content of FW, adjusting the initial concentration of organic matter. The growth of microbial communities was formed mainly by Clostridium sp. The co-digestion of FW:cornWW can be technically feasible to improve the production of H2 through the dark fermentation process.