Enhancement of fermentative hydrogen production by Thermotoga maritima through hyperthermophilic anaerobic co-digestion of fruit-vegetable and fish wastes

In this work, different proportions of model fruit and vegetable wastes (MFVW) and acid hydrolyzed fish wastes (AHFW) were used for hydrogen production in a minimum culture medium based on seawater. Experiments were performed in pH-controlled Stirred Tank Reactor (STR) with or without the addition of nitrogen and sulfur sources. The total H-2 production and the maximum hydrogen productivity of T. maritima in the culture medium, containing MFVW and AHFW (45 mmol L-1 carbohydrates) at a C/N ratio of 12, were 132 mmol L-1 and 15 mmol h(-1) L-1, respectively. However, tripling the concentration of carbohydrates to reach a C/N ratio of 22, has increased two times the maximum H-2 productivity (28 mmol h(-1) L-1) due to the improvement in nutrient balance. The cumulative H-2 production was 285 mmol L-1, yielding a potential energy generation of 0.1210(3) MJ ton(-1) wastes, which could be an interesting alternative for energy recovery