Nitrogen-phosphorus doped starch carbon enhanced biohydrogen production

Abstract

To solve the thermodynamic limitations on the hydrogen (H2) yield by dark fermentation (DF), the conductive carbons are usually used to mediate the H2-DF.In this work, the nitrogen (N)-phosphorus (N) doped starch carbon (NPSC) was prepared and characterized to investigate its influence on H2-DF. NPSC effectively raise H2 yield compared with starch-derived carbon (SC). The optimal dosage of SC (400 mg/L) and NPSC (600 mg/L) caused the highest H2 yield of 219.5 and 261.2 mL/g glucose, respectively, being higher than the control yield (161.4 mL/g glucose). Factually, compared with the control group without any carbon, NPSC optimized the microbial community structure and increased the abundance of C. butyricum from 19.09% to 30.87%. This fact increased the shift of metabolic pathway to butyric acid evolution, thereby promoting the substrate conversion level to H2.