Improving Biohydrogen Evolution from Glucose with Magnetic Activated Carbon

Magnetic activated carbon (MAC) was fabricated to improve biohydrogen (bio-H2) production. The MAC exhibited higher biocatalytic capability and better microbial immobilization than activated carbon (AC) during the bio-H2 process. Glucose supplemented with 200 mg/L MAC obtained the highest H2 yield of 214 mL/g glucose, much higher than that (130 mL/g glucose) of the control group without MAC. Suitable dosage such as 300 mg/L AC or 200 mg/L MAC promoted volatile fatty acid (VFA) formation and H2 generation. Besides, the metabolites showed that AC or MAC did not change the bio-H2 evolution pathway. Some possible biochemical mechanisms were as follows: MAC served as a microbial carrier to promote cell colonization and electron transfer rate, and it released Fe3+ to enhance glucose acidogenesis and Fe2+ to increase microbial concentration and activity in the bio-H2 evolution.