Hydrogen production from soft-drink wastewater in an upflow anaerobic packed-bed reactor

摘要

The production of hydrogen from soft-drink wastewater in two upflow anaerobic packed-bed reactors was evaluated. The results show that soft-drink wastewater is a good source for hydrogen generation. Data from both reactors indicate that the reactor without medium containing macro- and micronutrients (R2) provided a higher hydrogen yield (3.5 mol H_2 mol~(-1) of sucrose) as compared to the reactor (Rl) with a nutrient-containing medium (3.3 mol H_2 mo~(-1) of sucrose). Reactor R2 continuously produced hydrogen, whereas reactor Rl exhibited a short period of production and produced lower amounts of hydrogen. Better hydrogen production rates and percentages of biogas were also observed for reactor R2, which produced 0.4 L h~(-1) IT1 and 15.8% of H_2, compared to reactor Rl, which produced 0.2 L h~(-1)1 L~(-1) and 2.6% of H_2. The difference in performance between the reactors was likely due to changes in the metabolic pathway for hydrogen production and decreases in bed porosity as a result of excessive biomass growth in reactor Rl. Molecular biological analyses of samples from reactors Rl and R2 indicated the presence of several microorganisms, including Clostridium (91% similarity), Enterobacter (93% similarity) and Klebsiella (97% similarity).