¶¶¶Biohydrogen Production Amended with Nitrogen-Doped Biochar

Conductive materials play a vital role in electron transfer during the hydrogen (H-2) fermentation process. In this work, a novel nitrogen-doped biochar (NDBC) was produced from corncob to improve biohydrogen production at 37 degrees C. Material analysis revealed that the nitrogen-rich biochar (BC) had a specific surface area of 831.13 m(2)/g, which was slightly lower than that of the corncob-derived BC (944.09 m(2)/g), while the electrical conductivity of the former was 13.91 times higher than that of the latter. The highest H-2 yield of 230 mL/g glucose was obtained at 600 mg/L NDBC, which was higher than the corncob-derived BC (159 mL/g glucose) and control (without any BC) (140 mL/g glucose) group yields. The microbial community structure illustrated that NDBC greatly reduced the abundance of Dysgonomonas (9.2%) and increased the abundance of Clostridium butyricum (10.9%). The NDBC and corncob-derived BC materials played obviously different roles: the former enriched the dominant bacteria and acted as an electron conduit promoting electron transfer, while the latter mainly provided favorable sites for microbial colonization. The results also indicated that cleaner energy production with a high H-2 yield was attained with the nitrogen-doped BC material.

Automated summary

The study demonstrates that nitrogen-doped biochar (NDBC) can enhance biohydrogen production by promoting electron transfer with its significantly higher electrical conductivity compared to regular biochar, and by enriching dominant bacterial communities.